- "Rhaenyra Targaryen was murdered by her brother, or rather, his dragon. It ate her while her son watched."
- ―King Joffrey Baratheon
While touring the Great Sept of Baelor in King's Landing, King Joffrey Baratheon explains to Margaery Tyrell that Rhaenyra Targaryen was eaten by her brother's dragon while her son was forced to watch.
In the books
In the A Song of Ice and Fire novels, Aegon II took the Iron Throne at the behest of his mother, Queen Alicent Hightower, and Lord Commander Criston Cole of the Kingsguard, thereafter known as Criston the Kingmaker, even though his father, Viserys I, intended Rhaenyra, daughter of Viserys' previous consort, to succeed him. Rhaenyra disputed his ascension and claimed the throne for herself, leading to the civil war known as the Dance of the Dragons. Aegon managed to defeat his sister, and fed her to his dragon. Shortly thereafter he died himself, leaving no male heirs, which led to his nephew Aegon III, Rhaenyra's son, taking the throne.
Queen Alicent had three sons including Aegon II, as well as one daughter. Aegon II's younger brother Aemond rode the dragon Vhagar during the Dance. Following Targaryen custom, Aegon II married his sister Helaena. Aegon II had no male heirs, however, only two daughters, and at the end of the Dance Rhaenyra's son Aegon III solidified the peace by marrying Aegon II's daughter. The marriage ultimately proved to be childless, however, and Aegon III later remarried to a woman from House Velaryon, with whom he had all of his children. Thus later generations of the Targaryen dynasty apparently possess no descent from Aegon II.
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. Histories about the Dance of Dragons repeatedly describe Aegon II as both inexperienced and hot-blooded.
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. 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.
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. The Lannisters were wooed into his allegiance by naming their lord the new Hand of the King, but they frequently butted heads. 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.
- Aegon II Targaryen at A Wiki of Ice and Fire (spoilers from the books)
Kings of the Seven Kingdoms
Aegon I, the Conqueror · Aenys I · Maegor I, the Cruel · Jaehaerys I, the Conciliator · Viserys I · Aegon II · Aegon III, the Dragonbane · Daeron I, the Young Dragon · Baelor I, the Blessed · Viserys II · Aegon IV, the Unworthy · Daeron II, the Good · Aerys I · Maekar I · Aegon V, the Unlikely · Aerys II, the Mad