Okay kid, this is where it gets complicated...
The Dance of Dragons is the name given to the devastating civil war between two rival branches of House Targaryen, which lasted for three years from 129 to 131 AL, during which most of the Targaryen dragons were killed. So few dragons survived that they could not maintain a stable breeding population (i.e. maybe two or three). The last two dragons were sickly, stunted creatures not much bigger than large dogs, which died only a few years after the Dance ended. Ultimately, the Dance resulted in the believed extinction of the entire species of dragons - for about a century and a half, that is, until Daenerys Targaryen hatched three live dragons.
The events surrounding the Dance with Dragons have only been described vaguely and in passing during the main A Song of Ice and Fire series, but are the focus of the prequel novella titled The Princess and the Queen, released in December 2013. As such, there are still some gaps in our knowledge.
While the exact sequence isn't clear, the Dance of Dragons is meant to loosely parallel the real-life civil war between King Henry I of England's heirs. Viserys I had one female heir through his first marriage who was the assumed heir (Rhaenyra) but was usurped in a civil war by her half-brother from her father's second marriage (Aegon II). Similarly, Henry I had a single surviving heir apparent who was female (Empress Matilda), yet she was usurped in a civil war by a male heir from a younger branch of the family (Stephen).
The Great Council of 101 AL
King Jaehaerys I enjoyed a very long and peaceful reign of fifty-five years, from 48 to 103 AL. He ruled alongside his sister-wife Good Queen Alysanne, aided by his skilled Hand of the King, Septon Barth.
Jaehaerys I, however, was the only king in history who was succeeded by his grandson, skipping over his own son. For a long time it was assumed this may have been simply because he lived to such a great age, but there was also lingering suspicion that his son died young. Jaehaerys I's grandson was King Viserys I, who was also in general a good king. He ruled the Seven Kingdoms after a long era of peace and prosperity which continued into his own reign, and he seemed plump and amiable, without behaving gluttonous or self-absorbed. Viserys I originally married a woman from House Arryn. The fact that Viserys I didn't marry another Targaryen, as per their incestuous marriage customs, strongly implies that he was not near the head of the line of succession originally. Viserys I's mother was Rhaenys, named after the first Rhaenys who was the sister-wife of Aegon I. Rhaenys was later remembered as "The Queen Who Never Was" due to the fact that her husband was never crowned king, outlived by his own father, and thus the crown passed straight from Jaehaerys I to his grandson Viserys I. Rhaenys was the daughter of one "Aemon Targaryen" and Jocelyn Baratheon.
In 92 AL, the question of succession was raised, and Jaehaerys I declared that Baelon (apparently his son) would succeed ahead of Rhaenys. After Baelon apparently died suddenly in 101 AL, a Great Council was held to determine the heir - yet chose Rhaenys's son Viserys I ahead of Rhaenys herself (possibly because Rhaenys's husband was another Targaryen of superior rank, i.e. Baelon's younger brother?)
Given that the Dance of the Dragons is meant to parallel the succession crisis at the end of the reign of King Henry I of England, it appears probable that there was some sort of parallel to the "White Ship Disaster" - in which Henry I's original male heir was killed in a shipwreck, leaving his daughter Matilda as the only direct heir. Keeping that in mind, it seems that Baelon may have died unexpectedly, forcing the line of succession to go through Aemon and his children.
In any event, Balerion the Black Dread is also known to have died near the end of Jaehaerys I's reign, not in the Dance of Dragons. A possible narrative parallel is that Baelon and Balerion somehow died in a tragic accident (struck by lightening?). Balerion's skull is eventually recovered and seen in the Red Keep, so he wasn't simply lost at sea or something. Thus the entire reason that Jaehaerys I had a Great Council in 101 AL to clear up the matter of his line of succession might be because of a sudden death in the family (there wouldn't be another known Great Council until the death of Maekar I a century later).
King Viserys I (r. 103-129 AL)
Viserys I's one fault was in the folly of his remarriage, which would eventually tear apart the realm, though only after his death. He had two sons with his first wife but they died in infancy, and he had a single daughter with his Arryn wife: Rhaenyra Targaryen. Viserys I's Arryn wife then died, so since Rhaenyra was a little girl she was raised with the assumption that she would be the royal heir.
Viserys I later remarried to Alicent of House Hightower, the rulers of Oldtown, who gave him four children, including three sons and one daughter. Thus the seeds of the Dance of the Dragons were sown. However, Viserys I still publicly declared that Rhaenyra was his heir, and even had the great lords of the realm swear major oaths and sign legal contracts to confirm this. Alicent's four children were Aegon, Aemond, Daeron, and daughter Helaena.
Rhaenyra first married to the lord of House Velaryon, and had three sons with him before his death. However, many believed that the boys were actually fathered by Rhaenyra's lover Harwin of House Strong, current rulers of Harrenhal. Rhaenyra later remarried to her own uncle, Daemon Targaryen, younger brother of her father Viserys I. She had two sons with Daemon, the future Aegon III and Viserys II. Her sixth and last child, born to Daemon, was a stillborn daughter.
Alicent Hightower's palace coup: Aegon II usurps the throne
Aegon II started out as almost a puppet for his mother Queen Alicent Hightower, and at first, he did not even want to seize the throne. His mother only managed to get him to go along with the plan when she convinced him that Rhaenyra would eventually strike first and kill his daughters, because if his bloodline lasted one of his descendants might eventually challenge one of hers in the future
When Viserys I died in 129 AL, Queen Alicent kept his passing secret for as long as she could while assembling her loyalists into position in the Red Keep. Princess Rhaenyra was away at Dragonstone, resting as she was eight months pregnant. Alicent convened the Small Council and declared that her son would be crowned as Aegon II - with the support of the Lord Commander of the Kingsguard, Ser Criston Cole, afterwards remembered as "the Kingmaker", as well as her own father Otto Hightower, who had been Viserys I's Hand of the King for many years.
When Viserys I died and Queen Alicent staged the palace coup, the only member of the Small Council who spoke against Aegon II's succession was Lord Lyman Beesbury, an elderly man in his eighties who had skillfully served as Master of Coin for over thirty years, not only under Viserys I but even under his grandfather Jaehaerys I. Alicent had him executed as a result, but this hobbled Aegon II's Small Council by robbing it of an experienced Master of Coin, particularly given that they needed funds for the war. Actually, saying that old Lord Beesbury was "executed" is somewhat too formal: after trying to reason with Alicent and debating the matter at length, he realized that Alicent was outright trying to steal the crown, whatever the laws of inheritance said. Old Lord Beesbury defiantly said he would not idly sit by while Alicent and her son stole Rhaenyra's crown, and rose to leave. Unfortunately, he either didn't notice or didn't pay heed that Lord Commander Criston Cole was standing behind his chair at the council table. Just as Beesbury rose, Cole quickly forced the old man back down into his chair, and as part of one swift motion, opened up Lord Beesbury's throat. The Small Council spent the rest of the night planning Aegon II's coronation. Accounts differ: some say they adjourned to another room, many say that they continued their planning at the same table, now covered in Beesbury's own blood. A few say that in order to preserve the secrecy of the coup, Beesbury's body was left where it fell on the council table, and that Alicent and her supporters continued to nonchalantly discuss their plans at that same table while Beesbury's blood pooled across the surface.
The Lannisters were wooed into his allegiance by naming Tyland Lannister the new Hand of the King, but they frequently butted heads. Tyland was the twin brother of Jason Lannister (the current Lord of Casterly Rock), and had previously served as Master of Ships under Viserys I.
When news reached Rhaenyra on Dragonstone that her half-brother had declared himself king in opposition to her, she became so distressed that she went into premature labor and her daughter was stillborn, as well as badly deformed (similar to Daenerys Targaryen's stillborn son Rhaego generations later). Rhaenyra blamed her brother and his supporters for causing the death of her daughter, adding further fuel to her hatred of them.
At the outset, when Rhaenyra first declared war against the coup, Aegon II sent an envoy to her with relatively generous peace terms, offering her the continued rule of Dragonstone if she would submit to him. When she refused, however, something snapped in Aegon II, and he pursued increasingly vicious and ruthless action. As the three years of the war passed he came out from his mother's shadow and began making decisions in his own right - many of which actually hurt his cause.
The Blacks and the Greens
Needless to say, tensions between Princess Rhaenyra and Queen Alicent were always high. At one point some years prior to Viserys I's death, both wore extravagant gowns to a tournament: Alicent wore a green dress while Rhaenyra wore Targaryen colors, a black dress with red highlights. Two rival political factions had been forming around the two, and after this incident at the tournament the two factions became popularly known as "The Blacks and the Greens" (Blacks for Rhaenyra supporters, Greens for Alicent/Aegon II supporters).
The Seven Kingdoms were divided in the Dance of the Dragons, indeed, eerily mirroring the same pattern in which they would later split during Robert's Rebellion over a century later. Aegon II controlled King's landing and the mainland of the Crownlands, while Rhaenyra controlled Dragonstone and the islands in the Narrow Sea that are part of the Crownlands. The Vale and the North declared for Rhaenyra. The Riverlands were divided, as they often are, but many of the major Riverlands Houses sided with Rhaenyra, particularly their overlords House Tully, as well as Rhaenyra's close allies House Strong, who controlled Harrenhal. Thus Rhaenyra loosely controlled the northern half of the realm. The Westerlands supported Aegon II due to making Tyland Lannister Hand of the King. The Hightowers were of course Aegon II's biggest supporters, and despite being a vassal of House Tyrell were as strong as the Lords Paramount who ruled other regions of Westeros which were much poorer. The Reach, as a whole, did not side with one faction or the other, but was itself split. The current lord of House Tyrell was a young boy with a female regent, thus House Tyrell itself was in no position to fight and officially declared its neutrality. Other powerful Houses of the Reach, however, over whom they had a weak hold, did as they would. While the Hightowers provided massive aid to Aegon II's faction, a large number of Reach Houses also sided with Rhaenyra. The Iron Islands followed their usual strategy of being concerned only for themselves, and opportunistically shifting allegiance from one moment to the next depending on which side seemed to be in a better position to bribe them off. Dorne was not yet united to the realm and maintained its isolationist stance by staying out of these affairs.
The most crucial point is that at the beginning of the conflict, the Stormlands were on the fence, and both sides attempted to woo them into allegiance. Ultimately Storm's End joined Aegon II's faction, drastically changing the outcome of the war. If Aegon II only controlled the Crownlands, Westerlands, and Hightowers of Oldtown, he might not have been able to last for as long as he did - but the Stormlands entering into Aegon II's camp evened the odds and prolonged the war.
The Blacks: Rhaenyra Targaryen's faction
Targaryen incest practices reached quite a high degree in this era, exacerbated by multiple remarriages. House Targaryen had entered into a double-marriage alliance with their old allies House Velaryon, in which the brother-sister pair of Laenor and Laena Velaryon married the niece-uncle pair of Rhaenyra and Daemon Targaryen. Both Laenor and Laena later died, after which Rhaenyra married her own uncle Daemon. Both Rhaenyra and Daemon had remaining children from their previous marriages - who on the Velaryon side were also first cousins.
Complicating matters even further was that Rhaenys, Rhaenyra's paternal grandmother and the "Queen Who Never Was", remarried to Corlys Velaryon: Laenor and Laena were themselves the children of Rhaenys and Corlys. Rhaenys was already the mother of both Viserys I and Daemon. Thus Daemon's first wife Laena was actually his half-sister, and he later remarried to his own niece Rhaenyra - thus Rhaenyra's children with Daemon were also her own first cousins, while Rhaenyra's son Aegon III was both the second cousin once removed and half sister of Baela.
- Queen Rhaenyra Targaryen, First of Her Name. Daughter of King Viserys I and his first wife from House Arryn. Rider of the "she-dragon" Syrax.
Rhaenyra's first husband was Laenor Velaryon, rider of the dragon Seasmoke. After he died, Seasmoke would bond to no other, and lived out in a state of semi-retirement on Dragonstone.
Rhaenyra's children by Laenor Velaryon (rumored to be fathered by Harwin Strong):
- Jacaerys "Jace" Velaryon. Rider of Vermax.
- Lucerys "Luke" Velaryon. Rider of Arrax.
- Joffrey "Joff" Velaryon. A boy of twelve. Bonded to the young dragon Tyraxes, barely yet old enough to fly much less fight.
Rhaenyra's children by her second husband, her own uncle Daemon Targaryen (her father's younger brother):
- Aegon the Younger (the future Aegon III). A young boy, bonded with the young dragon Stormcloud, as yet too young to ride.
- Viserys the Younger (the future Viserys II). An even younger boy, possessing no dragon, only an egg (which never hatched).
- One stillborn daughter, whose death at the outset of the civil war fueled Rhaenyra's hatred of Aegon II.
Meanwhile, Rhaenyra's current husband and one of her major champions was Daemon Targaryen, younger brother of Viserys I. A super-Targaryen thought to be Aegon the Conqueror come again. A warrior and adventurer of boundless energy. Rider of the dragon Caraxes, whom he frequently rode in military expeditions to the Stepstones. Caraxes was thus not only one of the largest dragons Rhaenyra's faction possessed but the most battle-hardened. When Daemon rode astride Caraxes and the beast let out its roar, entire armies were known to flee before his coming.
Children of Daemon Targaryen by his previous marriage to Laena Velaryon:
- Baela Targaryen. Rider of the dragon Moondancer. A great warrior and one of the major champions of the Blacks.
- Rhaena Targaryen. Did not possess a dragon. She did once possess a small hatchling but it had died before this point, due to unspecified circumstances. Known as "Rhaena of Pentos" due to the city of her birth - her father Daemon frequently traveled and campaigned in Essos.
Further, Rhaenyra enjoyed the support of the dowager "Queen That Never Was" Rhaenys Targaryen, mother of Viserys I and thus Rhaenyra's paternal grandmother. Rhaenys was herself a dragonrider, bonded with "Meleys the Red Queen" (apparently a confirmed egg-layer).
The Greens: Aegon II's faction
Aegon II was the son of Queen Alicent Hightower, and was crowned king as the result of her palace coup.
Alicent Hightower had four children with King Viserys I, three sons and one daughter:
- King Aegon II. Rider of Sunfyre.
- Aemond One-Eye. Rider of Vhagar, last of the original Targaryen dragons, grown ever more great and powerful with age.
- Daeron. Rider of Tessarion, the Blue Queen (apparently a confirmed egg-layer, as Rhaeenys's dragon Meleys is called the "Red Queen").
- Helaena, Alicent's only daughter. Rider of Dreamfyre, who had once belonged to Princess Rhaena, older sister of Jaehaerys I and Alysanne. Following Targaryen custom, Aegon II married his own sister Helaena, and had three children with her.
- Jaehaerys and Jaehaerya, male and female fraternal twins, six years old at the beginning of the Dance. Each of them actually had their own hatchling dragons at the start of the Dance (i.e. the size of Daenerys's dragons in Season 2). Jaehaerys's dragon was named Morghul, and Jaehaerya's dragon was named Shrykos. These hatchlings were so small that they were often omitted from the count of dragons which Aegon II's faction possessed, which was usually given as only four.
- Maelor, a two year old son. Possessed no dragon.
An Index of Dragons
Dragons between the Conquest and the Dance
The main A Song of Ice and Fire novels consistently state that after the extinction of the dragons, the Targaryens continued to preserve nineteen dragon skulls on display in the Red Keep. This vaguely implied that there were only ever nineteen Targaryen dragons. However, information from The Princess and the Queen reveals that there had to be more than nineteen Targaryen dragons.
The Targaryens actually brought five dragons with them when the moved to Dragonstone from Valyria. Four of them died, leaving Balerion as the sole surviving Valyrian dragon. The other dragons did leave eggs behind, however, from which hatched Vhagar and Meraxes (who never saw Valyria). We don't know if the Targaryens preserved the skulls of these first four dragons.
During the Dance, the official number given was that Rhaenyra and the Blacks controlled twelve dragons, while Aegon II and the Greens controlled only four. However, Rhaenyra and Daemon both realized that many of their dragons were not battle-ready, and while Aegon II only had four dragons they were all powerful fighters ready for battle.
That being said, both sides apparently didn't include hatchlings in this count: dragons only counted if they were big enough to ride. Some of Rhaenyra's sons had dragons were were technically big enough to ride for long distances, but which she considered to be too young to have hope of fighting the older dragons possessed by Aegon II. For that matter, the Targaryens apparently only preserved the impressive-looking skulls of adult dragons, not hatchlings who suddenly died. Rhaena Targaryen is stated to have had a dragon, but it died before the Dance when it was only a hatchling. The last two of the nineteen skulls preserved in the Red Keep were only the size of a large dog's, and belonged to the stunted last dragon - they may have only been preserved because they were of the last known dragon.
The next record we have of the number of dragons extent at any one time is when Jaehaerys I and Alysanne rode six dragons to Winterfell - though this isn't necessarily all that they possessed at the time, i.e. some may have been too young to fly great distances. If an older dragon was left riderless it is unknown if it would still take part in the flight. Balerion was probably one of them as he only died near the very end of Jaehaerys I's reign. Alysanne rode her dragon Silverwing, and Jaehaerys I rode his dragon Vermithor. The dragon once ridden by their sister Princess Rhaena, Dreamfyre, was also alive at this time and later took part in the Dance of the Dragons (though it is unknown if it was one of these six).
King Aenys I bonded to a younger dragon named Quicksilver. It may have been of the same generation of Silverwing, following the naming scheme, and as both were presumably alive by the middle of Jaehaerys I's reign - though no subsequent mention has as-yet been found of Quicksilver in the Dance.
The exact genealogy of the dragons is not yet certain, though all Targaryen dragons descended from Aegon I's original three. Subsequent generations, after the dragons went extinct, forgot several key details about their biology. Dragons are said to have been mutable like flame, and could actually shift gender between male and female as the needs of the species required (as certain known species of amphibians actually do). Keep in mind that like other reptiles, dragons only have a cloaca and no external sex organs, so to the untrained eye, their biological sex was as difficult to easily determine as it would be for normal reptiles (like lizard-lions). Therefore few suspected that they could actually shift their sex. This knowledge wasn't entirely forgotten but was openly questioned by maesters of later centuries (though a few maesters adamantly insisted this was the case). Indeed, the mutability of dragon biological sex is evidence in the High Valyrian language, which uses many gender-neutral nouns. Dragons are usually referred to by default as "he" (in the sense of "it"), but it isn't clear if they start out as male but can switch to female, or if they are hermaphrodites that shift to either characteristic; surviving accounts seem to indicate that they're not outright hermaphrodites but shift from one biological sex to the other.
Several dragons are remembered as female, referred to as "she", even in later histories which openly doubt that dragons could switch sexes. With no other determinant, this indicates that dragons remembered as "female" are ones known to have laid eggs. Both Meraxes and Syrax are referred to as "she-dragons". Vhagar was also referred to as female. Dragons referred to as "Queens" were quite probably egg layers who had produced adult progeny (notably, "queen" is technically the proper term applied to female felines). Meleys was the "Red Queen" and Tessarion was the "Blue Queen".
Dragons who died before the Dance
Four out of five of the dragons which the Targaryens took to Dragonstone died, but disregarding these, only two adult dragons are known to have died before the Dance.
- Meraxes - Targaryen attempts to conquer Dorne during the initial War of Conquest were frustrated by guerrilla warfare. That Dornish would simply flee before the Targaryen dragons and armies, then harass their supply lines in the night. Faced with six other kingdoms to reign in, the Targaryens under Queen Rhaenys withdrew. Rhaenys apparently went on renewed campaigns in Dorne, and in the final one of these the Dornish were actually able to ambush and kill both Rhaenyra and her dragon. Meraxes is stated to have been killed with multiple crossbow bolts through the eyes. Dragons are powerful but not outright invincible, and sustained arrow fire can eventually take one down. Meraxes is referred to using feminine pronounes ("she"), which may imply that Meraxes laid eggs before it died.
- Balerion, the Black Dread. Died in unknown circumstances near the end of the reign of King Jaehaerys I. May have died in a catastrophe which also took the life of Jaehaerys I's son, resulting in the succession skipping to Jaehaerys I's grandson. Balerion probably didn't die naturally: dragons only grow stronger with age, not weaker, and no one is sure if they even can die of old age.
This only accounts for adult dragons, however: given the example of Rhaena, it isn't certain if hatchlings were born but died before adulthood in this time period, and were thus ignored by later historians.
Dragons during the Dance
The official count given of dragons at the start of the Dance was four for the Greens and twelve for the Blacks, but these numbers are misleading. The Blacks recognized that many of their dragons were either riderless or never even had a rider. Others, such as the dragons of Rhaenyra's sons, were included in the count of twelve because they could physically fly long distances, but were still very young and not really ready for battle against other full-grown dragons. Moreover, neither side included in this count dragons who were so young that they could not support a rider, which included two for the Greens (Morghul and Shyrkas) and one for the Blacks (Stormcloud).
Controlled by the Greens:
- Vhagar - ridden by Aemond One-Eye. Last of the original three Targaryen dragons, and originally ridden by Visenya Targaryen. As dragons only grow more powerful with age, Vhagar was now one of the most powerful living dragons, with 130 years of extra growth and combat experience compared to its already formidable prowess during the original War of Conquest (during which Vhagar had been the youngest and smallest of the original three Targaryen dragons).
- Sunfyre - Aegon II's dragon
- Dreamfyre - dragon of Queen Helaena, sister-wife of Aegon II. Originally belonged to Princess Rhaena, older sister of Jaehaerys I and Alysanne.
- Tessarion, the Blue Queen - Daeron's dragon.
Possessed by the Greens but not battle-ready:
- Morghul - bonded with Jaehaerys, son of Aegon II.
- Shrykos - bonded with Jaehaerya, twin of Jaehaerys and daughter of Aegon II.
Controlled by the Blacks:
- Syrax - ridden by Queen Rhaenya. Called a "she-dragon", possibly another egg-layer.
- Caraxes - ridden by Daemon Targaryen. One of the largest and most battle-hardened dragons of its day.
- Meleys, the Red Queen - ridden by Queen-That-Never-Was Rhaenys, Viserys I's mother and Rhaenyra's paternal grandmother.
- Moondancer - ridden by Baela Targaryen, Daemon's daughter from his first marriage to Laena Targaryen. His younger daughter Rhaena had a dragon at one point, but it died as a hatchling before the Dance.
Rhaenyra's three older sons, from her first marriage, all possessed dragons. They were all very young, however, and only the oldest two had dragons capable of flying. Their ability to fly long distances with a rider technically made them count as "battle-ready" but even Rhaenyra and Daemon were wary to send them into combat against other dragons:
- Vermax - ridden by Rhaenyra's eldest son Jacaerys "Jace" Velaryon. Sent on a mission to the Eyrie and the Winterfell to rally them to Rhaenyra's side.
- Arrax - ridden by Lucerys "Luke" Velaryon. Sent to Storm's End to try to sway it to Rhaenyra's side, only to accidentally arrive at the same time that Aemond arrived on the great dragon Vhagar, also seeking the same goal.
- Tyraxes - bonded with the youngest of Rhaenyra's oldest three sons, Joffrey "Joff" Velaryon, a boy of twelve. Tyraxes was barely old enough to support a rider's weight for short distances and could not really fly for long distances reliably - much less fight another dragon.
Rhaenyra's sons from her second marriage, to Daemon Targaryen, only had one dragon, too young to even consider using:
- Stormcloud - belonged to Aegon the Younger (the future Aegon III). Aegon himself was still only a child, and Stormcloud was too young to carry his weight at all.
Rhaenys's first husband Laenor Velaryon had ridden a dragon, but after his death it did not bond with another rider and was considered "retired" at the beginning of the Dance:
- Seasmoke - ridden by Laenor Velaryon, "retired" to Dragonstone without a rider
Dragonriders, dragon-bonding, "retirement", and "wild dragons"
Certain other dragons may have been in a state of temporary "retirement" because they had no current rider. After Aegon I died his son Maegor instantly bonded with Balerion, but perhaps sometimes a dragon would accept no new rider after the death of its previous one - possibly forever, sometimes for long gaps until it encountered a new rider who could easily bond with it. Silverwing and Quicksilver may have been among these, originally: as yet no mention has been made of Quicksilver in the Dance. Silverwing was active in the Dance, and may have been possessed by Aemon II's faction - but it wasn't included in the count of four "active" dragons, implying that it was in a riderless state at the beginning of the Dance, but it is known that it later actively fought in it.
Thus the initially riderless and "retired" dragons, from either side, included:
- Vermithor - the dragon of King Jaehaerys I, the Old King. Eventually ridden by Hard Hugh Hammer.
- Quicksilver - assuming it was still alive
"Bonding" with a dragon is a difficult and little-understood process, believed to be limited only to members of the Targaryen bloodline, the blood of Old Valyria which once rode dragons for centuries. Others say that this is a lie that Targaryens propagated to convince others that only they could ride the dragons so no one would try to steal them, a lie which later generations of Targaryens came to believe themselves. Whether this is true or not, or if it was a lie but Rhaenyra and Aegon II honestly believed it, cannot be easily determined. That being said, having Targaryen blood apparently helped when it came to bonding with a dragon. There were times, however, when a member of the Targaryen bloodline still proved incapable of bonding with a riderless dragon.
Usually there were more Targaryen heirs than there were dragons, but by the time of the Dance, the number of dragons had exceeded the known living members of the Targaryen bloodline. Apparently, unless a dragon is bonded with when it is a hatchling or at least very young, if it reaches adulthood without ever being bonded to a rider it will turn "wild". These "wild dragons" were not "found in the wild" out in Essos or the wreck of Valyria, rather they were adult dragons who had never known a rider, and thus grew so unruly that they were believed to be forever untameable. Rhaenyra's faction "possessed" three of these wild dragons during the Dance - in the sense that they nested on Dragonstone island, which she controlled. Growing up untamed, they flew and hunted about the island as they wished, terrorizing the commonfolk and stealing their livestock.
The original generation of Targaryen dragons had been named after the gods of Old Valyria. Some of the younger ones apparently continued this tradition, i.e. "Caraxes" and "Tessarion". Younger generations of Targaryen dragons were given elegant descriptive names, like "Silverwing" or "Moondancer". In contrast, the wild dragons were never bonded so they never received formal names, only loose descriptors applied to them by the commoners of Dragonestone. Thus the greatest of these wild dragons had the inelegant name "Sheepstealer", which it had earned when it was just a juvenile making off with farmers' sheep. These three "wild" dragons included:
- Grey Ghost
- The Cannibal
Search for the Dragonseeds
As the Dance progressed, Rhaenyra Targaryen realized that her faction had more dragons than it did riders (unlike Aegon II's faction). Thus a major goal of her faction in the war became the quest for the "dragonseeds" - forgotten Targaryen bastards from over the years. As was believed, only those who possessed the "blood of Old Valyria" could ride dragons, which made these forgotten bastards suddenly of vital importance to the entire war.
After a series of adventures not given in detail, the Blacks were able to find two such dragonseeds. The first was an unacknowledged bastard teenaged girl from the Riverlands, known only as Nettles, who had been living in obscurity and unaware of her royal bloodline. Nettles hadn't been acknowledged and thus didn't possess a special bastard surname. Despite spending her life until this point as a complete nobody, a bastard teenaged girl forgotten by the world, Nettles suddenly surged to the forefront of realm-wide affairs when she was discovered during the Dance. She became one of Daemon Targaryen's chief champions, and an able dragonrider. She may have even bonded with the ferocious Sheepstealer, previously thought to be impossible (both of them had been essentially abandoned and left to their own devices for many years by their relatives; perhaps they were of a kindred spirit). The second of the dragonseeds was an acknowledged bastard girl named Alys Rivers, described as a seer: she inherited the much rarer, latent Targaryen gift for prophetic dreams.
The Dance of the Dragons
A Note on Sources
The historical record always distorts, due to biased maesters and the fallibility of memory. Archmaester Gyldayn's famous account, The Princess and the Queen, was itself riddled with historical inaccuracies - due to Gyldayn's needlessly critical yet at times self-aggrandizing writing style. Even Gyldayn admitted there were things he simply did not know, in which case he presents known alternate scenarios - e.g. Gyldayn provided no less than three completely alternate accounts of how one of the major generals in the war died. This is not to entirely disparage Gyldayn: his account was one of the most accurate single volumes on the Dance for many years, even compared to histories written by contemporaries who had lived through it. Grand Maester Munkun's The Dance of the Dragons, A True Telling is riddled with blatant errors and glaring omissions, guilty of such a basic mistake as stating that Ser Byron Swann died attempting to kill Vhagar...when Vhagar was Aegon II's dragon, and Byron fought for Aegon II - Ser Byron was in fact killed by Rhaenyra's dragon Syrax.
Still, Gyldayn was overly fond of puns - "Lord Beesbury responded waspishly", and at times seemed physically incapable of writing a paragraph which did not contain at least one usage of the word "mayhaps". Overall, that later Dornish historian wrote a much more accurate and coherent account of the Dance of the Dragons in his Book of the World, which was even more detailed and extensive than Gyldayn's The Princess and the Queen (that Dornish historian's accomplishment was all the more impressive given that he completed his magnum opus after moving to the remote Free City of Lorath, "famed" mostly for its cold temperatures and herring).
In any case, the history of the Dance of the Dragons given here is severely limited, a brief summation of the conflict written by a struggling Acolyte of the Citadel, based primarily on poorly arranged notes he made about Archmaester Gyldayn's account. The Acolyte also left an apology letter at the beginning, explaining that at one point his only copy of The Princess and the Queen fell into the mud - several pages were completely lost and others half-ruined and difficult to comprehend. Given that Gyldayne's account was written in High Valyrian it has previously been accessible only to a handful of scholars. Efforts to produce an official translation into the Common Tongue for the benefit of the smallfolk are nearing fruition. In the short term, the Acolyte's account remains the only available summation - based on a battered copy of Gyldayne, badly translated, at times confusing major events and persons, and all based on Gyldayne's account which itself took historical liberties in the first place. Perhaps one day we can all look forward to the more definitive account in the Book of the World. As for the Acolyte, no one knows what exactly became of him. He became increasingly obsessed with the history of the Targaryen dynasty and the Dance of the Dragons in particular, withdrawing from public affairs to write in the isolation of his chambers at the Citadel for days if not weeks at a time. He was last seen the night a tremendous thunderstorm struck Oldtown. When the Seneschal entered the Acolyte's chambers to check on his well-being, he found candles still burning, stacks of manuscripts on the Acolyte's desk, and the shutters to his window thrust open, lightning strikes crackling in the sky behind them - in a fit of madness, the Acolyte had apparently run off into the night, but he left his summary of Gyldayn behind. The Acolyte's last, cryptic message was hastily scrawled atop a previous report he had written about royal policy towards the smallfolk in King's Landing during the Dance, which consisted of simply the declaration: "Burn them all. Burn them all. Exterminate all the brutes. Fire and Blood."
The Dance begins
At the outside of the Dance, there were twenty living dragons. Meraxes and Balerion were already dead. Quicksilver hasn't been mentioned but this count assumes it was still alive. At least one dragon was born but died as only a hatchling, which belonged to Rhaena Targaryen. It is unknown if other hatchlings had previously died before reaching adulthood.
The Greens possessed four battle-ready dragons: Vhagar, Sunfyre, Dreamfyre, and Tessarion. They also possessed two younger dragons, bonded to six year old boys and not yet old enough to fly: Morghul and Shrykas. They possibly also possessed the two "retired" dragons Quicksilver and Silverwing.
The Blacks possessed twelve dragons, though not all were battle-ready and several were riderless: Syrax, Caraxes, Meleys the Red Queen, and Moondancer were large and battle ready. Vermax and Arrax were very young, only just capable of flying long distances and not expected to be a match against other dragons, while Tyraxes was so young it couldn't even fly long distances. Stormcloud was not old enough to fly at all, and only bonded to a young boy. Seasmoke was considered to be "retired" and riderless. Quicksilver and Silverwing may also have been "retired" and riderless at first (though Silverwing may have been controlled by Aegon II). If Quicksilver was still alive, it is possible that Stormcloud was so young that it wasn't even formally included in the count of twelve dragons controlled by the Blacks, but instead Quicksilver was. The Blacks also "possessed" three wild dragons who nested on Dragonstone but which were initially riderless: Sheapstealer, Grey Ghost, and the Cannibal.
At the outset, Rhaenyra realized she needed to be patient if she was going to win back her throne, and that an immediate direct assault on King's Landing would be too risky: particularly because she had just had a stillbirth and was not in a condition to ride Syrax. So she sent out her two eldest sons, Jace and Luke, as emissaries to rally different regions of the realm behind her. Both of their dragons were still young, but thought at least capable of long-distance travel. Their younger brother Joff protested that he wanted to ride Tyraxes with them, but it was still too young to reliably fly such distances. Because Jace's mount Vermax was older, it was sent on what was thought to be the longer and more dangerous mission: first to the Eyrie and then to Winterfell. This mission actually went without incident: the ruler of the Vale at the time was a woman, not a regent but one who had inherited in her own right due to a lack of male heirs. Known as the "Maid of the Vale", she was a natural ally to Rhaenyra: the entire civil war was being fought over the question of a woman's right to rule. Moreover, Rhaenyra's own mother had been an Arryn and thus they possessed blood ties. The Starks of Winterfell, meanwhile, had always been vocal proponents of Rhaenyra, ever since the Great Council of 101 AL. It seems that she intervened and settled a dispute between the Manderlys and Dustins (or some such matter), resulting in the Starks, Manderleys, and Dustins voicing support for her at the Great Counil. Moreover, the honorable Northerners always took oaths very seriously, and after they had publicly sworn to King Viserys I that they would follow Rhaenyra as his legal heir, they meant to follow through on their promise (unlike the Lannisters, who broke their word and supported Aegon II. Much of the Riverlands also declared for Rhaenyra, including their overlords House Tully of Riverrun. Also among Rhaenyra's staunchest supporters were House Strong of Harrenhal - as Harwin Strong was rumored to be the real father of her three oldest sons. This put Rhaenyra in complete control of all lands North of the Trident River, and for a good deal south of it.
Aegon II continued to hold King's Landing and the continental Crownlands, while Rhaenyra controlled Dragonstone and the Crownland islands in the Narrow Sea (similar to how, in the War of the Five Kings, Joffrey Baratheon held King's Landing and the mainland while Stannis Baratheon held Dragonstone and the islands). Aegon II also won the support of the Lannisters by naming Tyland Lannister (former Master of Ships) as his Hand of the King. Some of the other regions of the Riverlands, always fractious, may have sided with Aegon II, though early on they gained control of the southern portions to control the Goldroad and link the Westerlands with King's Landing (again, much as Joffrey Baratheon did in the War of the Five Kings). Aegon II's major supporters remained House Hightower, though the Tyrells themselves were undergoing a regency at the time and thus stayed out of the war. The Reach was heavily divided, however, and several major Houses also declared for Rhaenyra. The Iron Islands fended for themselves, and Dorne remained independent an uninvolved.
Luke and his younger mount Arrax were sent on the comparatively easier mission of flying to Storm's End to woo the daughter of Borros Baratheon into a marriage-alliance. Given the initial alliances in the war, the support of the Stormlands would tip the odds in Rhaenyra's favor. Unfortunately, Aegon II had the same idea, so he sent his brother Aemond One-Eye to Storm's End riding the great dragon Vhagar. While not directly planning to intercept Luke, both Aemond and Luke arrived at Storm's End near the same time. Aemond demanded that Luke immediately fight him, but Borros chastised Aemond that he had already accepted Luke into his castle as an ambassador and guest, and he would not dare violate sacred Guest right by allowing Aemond to harm the boy.
Aemond and Luke left Storm's End by mutual agreement to engage in the first duel of dragons just outside of the castle. Unfortunately, the young Arrax was no match for the oldest and most powerful living dragon, and Vhagar killed Arrax and Luke. Dragons do not grow weaker with age, only larger and stronger, but the tradeoff is that an incredibly powerful and large dragon becomes less agile due to its sheer bulk. Thus a younger, smaller dragon does have the advantage of speed against an older one - though Arrax was a young stripling barely old enough to fly long distances, while Vhagar was the oldest and greatest of the dragons. Even so, Luke may have had some small hope of defeating Vhagar - but Aemond demanded that they fight immediately, and one of the driving rainstorms common around Storm's End was taking place. During heavy rain, younger dragons must exert all of their strength simply on staying airborne, negating their advantage of speed, while in contrast an older dragon has the extra strength to compensate for the storm winds. Thus the environmental advantages were clearly in Vhagar's favor, and Arrax didn't stand a chance.
Aemond subsequently entered into a marriage-alliance with Borros's daughter, and Storm's End declared for Aegon II - drastically prolonging the war. Queen Rhaenyra collapsed when word of Luke's death reached Dragonstone, and with him also died any hope of a diplomatic resolution. Both sides now assembled their armies for open warfare.
The Dance quickens
The Blacks set about rallying their remaining supporters in the Vale, the North, and the Riverlands. The Vale in particular was close enough to King's Landing that its lords feared attack from Aegon II's dragons. Upon learning of the death of his older brother, the young Joffrey Velaryon swore a bitter oath of vengeance against Aegon II and Borros, despite being only a twelve year old boy whose dragon Tyraxes had just recently grown big enough to fly. When eldest brother Jace returned from the North, he sent Joffrey and Tyraxes to the Vale. Joffrey was driven by desire for revenge and wanted to fly immediately against the Greens, but grudgingly relented when Jace explained that he wanted him to defend Gulltown against probable attack from Aegon II's dragons. With him was also sent Rhaena, Daemon's younger daughter from his first marriage (and thus Joff's half-sister) - while she possessed no dragon she did bring with her three dragon eggs, and she prayed over them daily that they might hatch. Rhaena had been betrothed to Luke and was distressed by his death. Meanwhile, Rhaenyra's younger sons from her second marriage were sent away from Dragonstone: Aemon the Younger (the future Aegon III) along with his dragon Stormcloud, as well as Viserys the Younger (the future Viserys II) were both transported under heavy escort to the Free City of Pentos, where Daemon had spent much time in the past and had many contacts.
Having lost Arrax, Rhaenyra and Daemon began the quest for the Dragonseeds, to find forgotten Targaryen bastard children to ride their unbonded dragons. This search discovered Nettles, a bastard teenaged girl from the Riverlands, who rose to become one of Daemon's chief lieutenants and a major dragonrider. Meanwhile, none could stand before the might of Caraxes as Daemon rode him into battle. One of Daemon's other main lieutenants on the battlefield and fellow dragonrider was his daughter Baela Targaryen (from his previous marriage to Laena Velaryon), who rode the dragon Moondancer. Eventually Rhaenyra recovered enough to ride Syrax.
Having secured the support of the Stormlands, the Greens decided to go on the offensive. Their grand strategy was to advance in three areas simultaneously:
- Assemble a large sellsail fleet hired from the Free Cities to assault Dragonstone itself
- Send the main Green land army, with Tessarion, north up the Kingsroad to confront Rhaenyra's supporters at the mainland, who were concentrating at Harrenhal.
- Aegon II would personally ride out on his dragon Sunfyre to bring the Vale to heel.
Rhaenyra's local garrison at Dragonstone, drawn from the other island-based Houses of the Crownlands such as Velaryon and Celtigar, was still very small (though Duskendale had sided with Rhaenyra). Lord Corlys Velaryon was named Rhaenyra's Hand of the Queen. The Vale and the North were massing armies in support of Rhaenyra, as were the Tullys at Riverrun and the Strongs at Harrenhal, but a quick strike against Rhaenyra at Dragonstone might cut off the proverbial dragon's head and put an immediate end to the war. They also realized that almost equal to Rhaenyra in leadership of the Blacks was her husband/uncle Prince Daemon Targaryen - thus a massive strike against Dragonstone might be able to kill both Rhaenyra and her faction's greatest champion in one fell swoop. Joffrey was at Gulltown and Young Aegon and Viserys were in Pentos, but the Greens believed that the Starks, Arryns, and Tullys wouldn't keep fighting for them as they had for Rhaenyrs and Daemon.
The problem was that, for the time being, the Blacks edged out the Greens in naval superiority. House Velaryon's massive fleet, much of the original royal fleet under Viserys I, had sided with Rhaenyra. The only other navy of comparable size was the iron fleet, but Dalton Greyjoy played coy about siding with either side, as a prelude to declaring the Iron Islands an independent kingdom. The Hightowers and the Reach did have sizable fleets, but they were being held back to defend King's Landing itself. Therefore, Aegon II decided to hire a vast fleet of sellsails from the Free Cities - Tyrosh, Lys, Volantis, and others. The downside was that the mercenary fleets were hired at kingdom beggaring cost, even as half of the realm was in open rebellion, and the execution of Lord Beesbury robbed Aegon II of a skilled Master of Coin to replenish such funds.
The main Green land army advanced slowly north up the Kingsroad, aiming towards Harrenhal, seat of Rhaenyra's major supporters House Strong (and also in the general direction of her other main supporters, Riverrun, the Eyrie, and Winterfell). The army was led by Prince Daeron, who rode the dragon Tessarion, using her to scout out enemy movements and fortifications ahead of the core host.
Battle of Rook's Rest
While the main military campaign was driving north towards Harrenhal, Aegon II himself rode out on his dragon Sunfyre headed for the Eyrie. His hope may have been to quickly swing the Vale back into allegiance just as Vhagar's arrival at Storm's End had with the Stormlands - or he may have simply wanted to kill the Maid of the Vale and burn all of the Vale lords before they could assemble their armies. As Aegon II was heading towards the Vale, however, he stopped at the town of Rook's Rest, just west of Crackclaw Point. Word reached the Blacks, and the elderly Queen-Who-Never-Was Rhaenys flew out on Meleys the Red to intercept him. After a stunning battle, Rhaenys and Meleys were killed, but this was not the one-sided duel between Vhagar and young Arrax. Meleys was almost as old and large as Vhagar herself, and Rhaenys a skilled dragonrider, and they managed to grievously injure both Sunfyre and Aegon II, knocking both out of the war for an extended period of time. Sunfyre was so badly hurt that it could not fly, and was grounded at Rook's Rest, though it later recovered. Aegon II himself was badly burned with dragonflame: he was quickly transported back to King's Landing, and kept heavily sedated with Milk of the Poppy (to the point that he was unconscious for extended periods of time).
Jace then devised a daring plan: with Tessarion in the Riverlands and Sunfyre injured and stationary at Rook's Rest, this left Vhagar and Dreamfyre as the only adult dragons to defend King's Landing - and most felt that Aegon II's sister-wife Helaena, rider of Dreamfyre, was no warrior. Jace reasoned that the capital city was relatively unguarded, and that a bold assault using Syrax, Ceraxes, and Vermax might be able to take the city. Rhaenyra had favored a long-term plan, but the Blacks eventually agreed that with two of Aegon II's dragons away, this was an opportunity they could not pass up. Plans were begin to launch an attack against King's Landing - but the Greens attacked Dragonstone first.
Battle of Dragonstone
Aegon II and Sunfyre may have been badly wounded, but the assault on Dragonstone was already imminent. The sellsail ships were filled with archers for attacking Rhaenyra's dragons. All were instructed to remain calm and try to pick off the dragonriders, because a dragon
Jace, riding Vermax, was killed by a ship filled with Lysene archers - these men were veterans of conflicts in the Steptones which Caraxes had taken part in, so they were not terrified by the simple appearance of a dragon, but stood firm. No man could have questioned their bravery. Ship after ship exploded into fireballs from Vermax's breath, but the Lysene ships responded with a hail of arrows. Worse, Vermax was then set upon by ships fitted with large ballista crowsbows which fired harpoons attached to heavy chains. One struck Vermax in the belly, and like a man trying to yank out an arrow, tugging at the chain only tore open Vermax's belly even more. Ultimately Jace and Vermax succumbed to their sustained arrow-fire, and Vermax crashed into the Lysene archers' own ship, causing it to start sinking. Vermax was still alive but was too wounded to fly, and drowned along with the ship.
The sellsails from the Free Cities fought on, and for a time it appeared that they might take the island. There were other dragons to fight, but their captains assured them that they simply had to take out the riders. Suddenly, however, the sailors discerned winged shapes wheeling around the Dragonmount: the riderless dragons who had been nesting on Dragonstone joined the battle against them. These included Silverwing, Seasnake, Vermithor, and even Sheepstealer - all of the "retired" and "wild" dragons. The men of the Free Cities were shocked, as they had believed that riderless dragons would ignore them (much like how a riderless horse will not attempt a cavalry charge). As it turns out, dragons will also attack if they perceive that their home nesting area is under attack - and killing Vermax didn't exactly endear the sellsail fleet to the other dragons either. They proceeded to overwhelm and burn the entire fleet. This destroyed Aegon II's naval power in the east, as well as the large number of soldiers who were being transported in the ships to assault Dragonstone.
Fall of King's Landing
Jace and Vermax may have died in the battle, but Jace's plan to strike King's Landing was now more opportune than ever: not only were Sunfyre and Tessarion away, but most of the local garrison and sellsail fleet which had been protecting it were destroyed in the failed assault in Dragonstone. King's Landing was wide open - and the Blacks realized that the riderless dragons, while not as effective as dragons with riders, would still be useful in evening the odds. Even worse for the Greens, they foolishly divided their forces under the assumption that their sellsail fleet would actually take Dragonstone: Prince Aemond One-Eye left the capital city to join Tessarion in the assault on Harrenhal. Now only Queen Helaena and her dragon Tessarion remained in King's Landing.
When the Blacks' fleet and dragons arrived in the bay outside of King's Landing, they smashed into the few remaining defenders from the Greens. The Hand of the King wasn't present in the city, and King Aegon II himself was still badly burned and sedated into unconsciousness with milk of the poppy, so the defense of the city fell to Dowager Queen Alicent Hightower herself. She had started this war, but now it had come to her doorstep. To her credit, Alicent rose to the occasion and tried to organize the defense of the city as best she could. Against Alicent's credit, however, is the fact that her palace coup had been just plain sloppy. Not only had she simply assumed that Rhaenyra would roll over and accept having her crown stolen, but she botched the needed step of removing those loyal to the previous regime from power. True, she had executed poor old Lord Beesbury, but that left the Greens without a skilled Master of Coin to replace him. The problem was that, apart from a handful of new officers the Greens appointed, the overwhelming majority of the City Watch were still deeply loyal to Prince Daemon. Each of the seven gates of the city were commanded by officers picked for their loyalty to the Greens - but as soon as Caraxes appeared in the sky about the Red Keep, all of them were either arrested or murdered by their own men, and all seven gates of the city were flung open.
Prince Daemon landed Caraxes in the court of the Red Keep itself. Meanwhile, the riderless dragons were set loose on the main city, including Sheepstealer, Silverwing, and Vermithor. They had been meant to frighten or burn out the few remaining defenders, but the drawback of using riderless dragons was that they simply could not be controlled very well. True, using the riderless dragons had been a calculated gamble and it did succeed in establishing overwhelming superiority over the remaining Green defenders. Unfortunately, without riders to control them the riderless dragons began burning the entire city, indiscriminately. Untold thousands of smallfolk were killed, more unhoused.
With the battle over, Rhaenyra and the Blacks set up camp at the Red Keep. Both Dowager Queen Alicent and Queen Helaena had been captured - the attack came so suddenly that Helaena was unable to even mount Dreamfyre (given that she spent most of her time weeping in her castle chambers, as she had one been friendly to Rhaenyra and was deeply upset by the war and deaths of her sons, her half-nephews). Many other Green supporters were also taken prisoner. King Aegon II had apparently been secreted out of the city during the assault. Rhaenyra's Hand, Corlys Velaryon, supported the idea of granting the Greens generous and lenient peace terms, to quickly restablish peace. Rhaenyra, however, was now embittered by the loss of all three of her sons from her first marriage. Lord Corlys had suggested that Alicent and Helaena be forced to join the Silent Sisters, and that all of the male Greens be forced to join the Night's Watch. Rhaenyra did pragmatically point out that oaths had meant nothing to the Greens when they broke the contracts they had made to her father, stole her throne and gave it to Aegon II, so there was little reason to trust them with any oaths again. Prince Daemon agreed that the Greens were utterly untrustworthy, and it would be more prudent to kill them all and give their lands to lords who had stayed loyal to Rhaenyra. Corlys was horrified, and accurately pointed out to Rhaenyra that even if the Green prisoners did not keep their vows of surrender (to the Faith and the Night's Watch), many lords who currently supported her would be horrified by such a breach of conduct as to execute defenseless prisoners. Rhaenyra would have none of it. Dowager Queen Alicent and Queen Helaena were executed. Daemon proposed to raise up Hard Hugh Hammer as the new lord of the Westerlands, and to replace Borros Baratheon with Ulf White as the ruler of the Stormlands. These decisions would have disastrous repercussions later in the war. With Helaena's death, the Blacks succeeded in capturing Dreamfyre, as well as the young dragons Morghul and Shrykos in the Dragonpit.
Battle of Harrenhal
Of the Greens' three-pronged goals, Aegon II's personal raid against the Vale on Sunfyre had ended before it began with a surprise upset, and their navy's assault on Dragonstone had been a catastrophic failure. King's Landing was now in Rhaenyra's hands. Yet simultaneously with the Blacks' seizure of the capital city, the main Green field army under Prince Daeron had begun to assault Harrenhal. Daeron rode Tessarion, and had been just recently joined by Aemond One-Eye riding the dreaded Vhagar. Prince Daemon flew Caraxes to Harrenhal, leading the main Black armies. Some of the riderless dragons were now ridden by the recently discovered "dragonseeds", forgotten Targaryen bastards, such as the teenaged girl Nettles, as well as Alys Rivers.
The titanic battle which resulted at Harrenhal was one of the main engagements of the entire war. Vhagar's clash with Arrax had only been a duel between two dragonriders: now two major opposing armies engaged each other as multiple dragonriders fought in the air. Many pivotal events occurred at the Battle of Harrenhal, but chief among these was the epic confrontation between Aemond and Daemon, riding Vhagar and Caraxes respectively. Vhagar was the oldest and most powerful surviving dragon, while Caraxes was also full-grown and had a great deal of combat experience throughout its life fighting on foreign campaigns in the Stepstones. Vhagar had previously killed the young Arrax without much challenge, but the fight between Vhagar and Caraxes was akin to a duel between living gods. Vhagar had killed Arrax during a rainstorm, which negated the very young dragon's advantage of speed. Caraxes was much larger and experienced than Arrax, and because it was a clear day at Harrenhal, could also use its slight advantage in agility over the older dragon. Daemon slammed into Aemond's dragon from his blind side, and the roars of their dragons shook across Gods Eye lake. Finally, Caraxes killed Vhagar, and Aemond plummeted to the ground atop her. Badly injured in the fall, Aemond One-Eye looked up to see that his uncle Daemon had dismounted and was approaching him, wielding Dark Sister, the sword of Queen Visenya. In terror, he desperately fumbled with the chains which bound him to his saddle, but he was too injured to flee. Daemon reached Aemond, wordlessly stripped off Aemond's helmet, and then drove his sword down point-first through Aemond's blind eye, killing him. Thus were Lucerys Velaryon and Arrax avenged, and thus did the last of the original three Targaryen dragons die. But it was not the end of the war, for the Blacks had also taken grievous losses that day. Tessarion had also survived the battle and would continue to fight in the war.
The Anarchy of King's Landing
Dowager Queen Alicent's short-sighted mistake had been when she didn't realize that most of the City Watch was still loyal to Prince Daemon. Yet Queen Rhaenyra made a similarly short-sighted mistake when her forces opportunistically captured King's Landing: she had not considered how she would feed its massive population. Maybe she had thought that the rest of the Greens would surrender after the capital was lost - but when she executed all of her Green prisoners after the fall of the city, including Alicent and Helaena, all of the surviving Greens realized this was a fight to the death. The problem was that the Greens still controlled the Westerlands and much of the Reach - no food supplies would be coming up the Roseroad from House Hightower now. Meanwhile, the campaign of the Green's main field army in the Riverlands cut off food supplies from that breadbasket region as well. Worse, for months previously, the Blacks' superior naval forces had been blockading King's Landing by sea, so food supplies in the city were already growing scarce even before Rhaenyra captured it. Supplies could still be sent up the Roseroad by land, but large transports of food by sea had become impossible, as well as imported foodstuffs from the Free Cities.
Thus while the Blacks appeared to have won the war after the double victories at King's Landing and Harrenhal, in reality King's Landing had been reduced to a burnt-out husk whose basic food needs the Blacks could not possibly sustain. When the Dance began, Rhaenyra had been very reluctant to dragons to take the city, even ones with skilled riders such as herself on Syrax or Daemon on Caraxes, because she didn't want to damage a city which by rights belonged to her. When Rhaenyra finally relented and the Blacks used riderless dragons against the city, it was gutted by flames - using the dragons was the easy path, but also the reckless path. So many of the smallfolk had died in the uncontrolled fires that their surviving family members were embittered against them. Many more were left homeless, and now starvation conditions set in for most of the city: the commoners of the city soon lost any love they may have had for the Blacks. Numerous street riots erupted, and their violent suppression only encouraged more riots. The Blacks were angered that the commoners didn't seem to care about defeating the Greens. The smallfolk, meanwhile, were angry that the nobles of Westeros honestly did not seem to care about their wellfare: Greens or Blacks, most of them had never met Aegon II or Rhaenyra, and now their homes and loved ones had been destroyed with dragonflame over a succession crisis between high lords that they didn't even know. Now, as they watched their children starve to death and bodies went unburied in the streets (both from the initial fiery fall of the city and subsequent riots), there were thousands of angry smallfolk in the city who truly had nothing to lose.
Soon, matters reached a breaking point. Yet another angry mob began to riot over food, but it was larger than any of the previous ones and the Blacks didn't have enough regular soldiers to provide crowd control. It quickly grew into a city-wide riot, as the human wave of the mob surged through the streets, thousands strong. They somehow had enough coordination to realize that they could never hope to assault the Red Keep, so the wave moved towards a different target: the Dragonpit atop the Hill of Rhaenys. Queen Rhaenyra watched from the Red Keep as the entire spectacle unfolded below her, lit by advancing torches. So much suffering in the "Dance of the Dragons" had been brought about by fighting between rival kings and queens riding dragons, it was dragons who burned much of King's Landing, and it was against the dragons that the mob now turned its rage. The Dragonpit did have its own guards but they were overwhelmed by a human crush of hundreds, quite probably thousands, of starving commoners.
Literal heaps of burnt corpses were left in the Dragonpit by the following morning, piled so high and so densely that a man could walk from one side to the other on them without needing to touch the ground. Few men lived to tell the tale of what had happened. Reports varied wildly even at the time, and the full truth may never be known. But what can generally be gleaned from the few survivors is that the noise of the mob, particularly when they assaulted the guards, had awoken all four dragons chained up inside. Maybe the mob had thought to take them asleep and unawares, if they had even thought that far ahead, but when they breached the sand-filled interior of the massive Dragonpit, all four dragons were alert and pouring forth dragonflame. With nothing to lose and angered to the point of madness, a human tidal wave charged headlong at the beasts, starving commoners armed with naught but axes, clubs, boards with nails in them, their own teeth and fists. Blinded by rage, their attacks were animalistic - they didn't even think to pull back to a distance and assault the dragons with hunting bows any of them possessed. The result was akin to watching a lion being swarmed by ants. Untold numbers of smallfolk were burned alive, but for each who fell ten more surged forward to take his place. The mob of the living pushed the still-standing corpses forward in a human crush. The main target of the mobs were the younger dragons, the ones not yet old enough to carry a rider long distances (i.e. like Daenerys Targaryen's dragons by the end of Season 3, or slightly older). The mobs would have torn young nine year old Prince Aegon as well as Prince Viserys to pieces if they had been in the capital and not sent away to the safety of Pentos - the young dragons would have to do in their stead. Shrykos died first, after one man managed to climb its neck and repeatedly heaved down his axe until it cracked into her skull. Morghul died as well.
While the riots initially targeted the Dragonpit, they spread city-wide, and the Blacks simply did not have enough soldiers to contain them. They had won the city using dragons, but dragons cannot be used as city guards. The main armies of the Blacks were in the Riverlands, and Rhaenyra had only brought her small home garrison from Dragonstone and the Houses of the Narrow Sea to the city - they were too few to restore order. Perhaps the Blacks had thought that fear of their dragons could intimidate the smallfolk of the city into submission, but the assault on the Dragonpit demonstrated that these were desperate, starving men who had nothing to lose, and thus didn't know fear anymore.
The Blacks became besieged within the Red Keep by the riots, and the city descended into true anarchy. Shops which the dragons and the battle hadn't touched were now torched and gutted by angry mobs. In time, the mobs began carving out their own tiny fiefdoms and areas of control within the city. In mockery, lesser knights leading some of the mobs - who had nothing to do with the Targaryens - began crowning themselves "king" of the streets they controlled, sarcastically claiming to be unrecorded Targaryen bastards. The Blacks had to withdraw from the city, while the Greens did not have the strength to reclaim it either. The capital city degenerated into a bizarre urban no-man's land controlled by neither side, prowled by rival mobs fighting amidst the ruins.
Turns of fortune and treachery
Rhaenyra had faced numerous setbacks, and in time, the Greens did retake King's Landing from the mobs. However, it started to become apparent that Aegon II was not a very fit king. Rhaenyra formed her own rival Small Council, and by all accounts, was a skilled administrator who was respected by the council members. In contrast, Aegon II was so inexperienced, untrained, and hotblooded that he was frequently at odds with his own Small Council. One of the reasons Rhaenyra's faction was able to gain so much ground despite not controlling the capital city is because of the fact that Aegon II could not adequately make use of those advantages he did possess.
Later histories often remember Rhaenyra Targaryen as arrogant, because she had been raised as the heir presumptive most of her life. Conversely, this meant that Rhaenyra had been actively trained to rule for many years, and even took part in her father's council meetings. Thus while Rhaenyra may have had a sense of authority and entitlement, it was because she possessed the actual administrative skill to back it up (in much the same sense that while Jaime Lannister was cocky and self-assured about his swordfighting skill, this was because he was officially recognized as one of the best swordsmen in all of Westeros). Aegon II's faction staged the coup against Rhaenyra on the grounds that she was arrogant (if skilled), but it soon became apparent that Aegon II was both arrogant and unskilled at rule. This should have come as little surprise, given that he was still a young man when the Dance broke out, only about twenty two-years old. Being physically a decade younger than Rhaenyra meant that he could not have had as many years of training and experience as she did. Further, he wasn't even as experienced or skilled as Rhaenyra was at his age, because unlike her he had not received thorough training in rulership since he was a child. He wasn't quite insane or as unruly as the later Joffrey Baratheon was, and he did have some rational mental capacity, but overall he was petty, arrogant, unskilled, short-sighted, and self-centered (sort of like a male Cersei Lannister). Histories about the Dance of Dragons repeatedly describe Aegon II as both inexperienced and hot-blooded: one Dornish historian later outright described Aegon II as a "slimeball".
Soon, Aegon II's shortcomings were starting to become all too apparent. Many who had initially sided with him because they thought he would assuredly win against Rhaenyra began to question their decision, and he lost many fair-weather allies. Many of those who stayed loyal to Aegon II were those who wanted to use him as a puppet to gain more power and other favors. Others realized that they had to keep fighting, because they had already crossed the line and Rhaenyra would never forgive their betrayal, or spare their lives, if she won the war.
For a time, the Blacks seemed to be winning. But what cannot be accomplished on the battlefield is often accomplished through treachery. This next phase saw the rise through the Targaryen ranks of Hard Hugh Hammer, who sought make himself king. He rode the dragon Vermithor.
Through treachery, Queen Rhaenyra was somehow captured by the Greens. Aegon II publicly executed her by feeding her to his dragon Sunfyre, while forcing her son to watch (who would later grow up to become Aegon III). The war did not end, however, as Rhaenyra's loyal followers still struggled against Aegon II in the hope of putting her remaining children on the throne.
The Final Dance
The final battle of the Dance of the Dragons involved a gigantic battle royal between all surviving dragons at once: the Second Battle of Tumbleton. Hard Hugh Hammer's army was encamped at Tumbleton in the northeast of the Reach, not far from King's Landing, while the three dragons his faction controlled were in the surrounding fields: Vermithor, Tessarion, and Silverwing. They came under sudden attack from an opposing army with Seasmoke at its head. Three dragons fought that day: Seasmoke was the first to die, when Vermithor bit its head off and flew away with it. Vermithor was so badly wounded, however, that it could no longer fly and died of its injuries not long after killing Seasmoke. Tessarion was also badly wounded in the fight, and while attempting to fly away was picked off by an archer from House Blackwood. Silverwing had avoided the fight entirely, instead circling around in the air high above the battlefield for hours.
When the dust settled, a tentative peace plan was devised to unite the two branches of House Targaryen: Rhaenyra's son Prince Aegon the Younger (Aegon III) would marry Aegon II and Helaena's daughter Jaehaerya. The marriage was conducted and Rhaenyra's son was crowned as Aegon III, but the marriage proved childless and Jaehaerya eventually died (it is unclear if fowl play was suspected). Aegon III later remarried to a woman of House Velaryon, by which he had all of his children. Both of Aegon III's sons eventually died childless, and due to the new male-preference succession laws installed after Rhaenyra died, the throne passed to his younger brother Viserys II. Thus later generations of the Targaryens are descended from Rhaenyra's son Viserys II, not Aegon II, though it is unknown who Viserys II's wife was.
In time, Viserys II was succeeded by his son Aegon IV the Unworthy, one of the worst kings the Targaryen dynasty ever produced. A self-obsessed glutton, Aegon IV fathered numerous bastard childre, including four "Great Bastards" whom he acknowledged because they were born to noblewomen. One of these, Daemon Blackfyre, was actually the product of an affair between Aegon IV and Aegon III's daughter Daena. Many cited that under normal Andal succession law, the throne would pass to a daughter (Daena) before an uncle (Viserys II), and thus Daena's son Daemon was the legitimate heir, ahead of Aegon IV's legitimate son Daeron II, whom he had with his sister-wife Naerys (though some suspect Daeron II was the product of an affair between Naerys and Aegon IV's brother Aemon the Dragonknight, either way Aegon IV and Aemon were sons of Viserys II). Ultimately, this means that the subsequent main branch of the Targaryen family descends from Rhaenyra's son Viserys II, while the rival cadet branch of the Targaryens known as House Blackfyre claims (illegitimate) descent from Rhaenyra's son Aegon III.