Kinslaying is the act of slaying a family member and a great taboo in Seven Kingdoms. Whoever commits it is dubbed a kinslayer. Any individual who slays a member of their own family is believed to be cursed forever in the sight of gods and men.
The taboo associated with kinslaying is strong enough to stay the hand of even the most ruthless men. Tywin Lannister would have liked nothing more than to kill his son Tyrion the day he was born, because his mother Joanna Lannister died giving birth to him and for the shame he brought on their family for being born a dwarf. However, Tywin felt that House Lannister was above the shame and curse of kinslaying, so he relented and let Tyrion live.
If a mother dies in childbirth, her offspring is not considered a kinslayer by the aforementioned faiths because there was no intent and it wasn't really their fault. The reactions of family members to the child can still vary, however, as sometimes they irrationally blame the child for the mother's death. Tywin always blamed Tyrion for "killing" his mother since she died giving birth to him, as did his sister Cersei Lannister. In contrast, his brother Jaime Lannister insisted that it wasn't his fault and always treated Tyrion with kindness and respect.
- Prince Daemon Targaryen, who slew his nephew Prince Aemond Targaryen during the Battle Above the Gods Eye.
- King Aegon II Targaryen, who fed his half-sister Rhaenyra Targaryen to his dragon.
- Prince Maekar Targaryen, who accidentally dealt a mortal head injury to his brother, Prince Baelor Targaryen during the trial by seven of Ser Duncan the Tall.
- Robert Baratheon, who killed Rhaegar Targaryen, who was actually his cousin due to intermarriage between the Baratheons and Targaryens.
- Craster, who sacrificed his male offspring to the White Walkers.
- King Stannis Baratheon, who conceives a shadow assassin with Melisandre to kill his brother Renly Baratheon.
- Stannis becomes a kinslayer once again, along with his wife, Selyse, when they allow Melisandre to burn their daughter Shireen in the belief that R'hllor will allow them to survive to reach Winterfell and defeat House Bolton. Selyse feels remorse and attempts to save Shireen, but by then it is too late. Stannis feels he has no choice, as divine intervention from the Lord of Light was Stannis's only chance to move past the heavy snows. 
- Ser Jaime Lannister, who murders Alton Lannister, his distant cousin, in his attempt to escape captivity.
- King Robb Stark, who is accused of it by Lord Rickard Karstark when the former is about to execute the latter for treason. However, this was due to the distant blood ties between House Stark and House Karstark hence it is debatable if Robb would be officially labelled a kinslayer as a result.
- Tyrion Lannister, who murders his father, Tywin Lannister. Tyrion later sarcastically quipped that because his mother Joanna died giving birth to him, from a technical standpoint he had "killed" both of his parents, making him the greatest Lannister-killer alive.
- Obara Sand, who murders her cousin, Trystane Martell, in a plot to take over Dorne. The three eldest Sand Snakes also go along with Ellaria Sand's murder of Doran Martell, with Tyene killing his guard Areo Hotah, though it is Ellaria that personally kills Doran. Ellaria was the paramour of Doran's brother Oberyn, and though not related to him by blood or marriage, he was still the blood uncle of her four daughters, including Tyene.
- Ramsay Bolton, who murders his own father Lord Roose Bolton after the birth of his trueborn half-brother. Ramsay did this for fear that his father would disinherit him for his failures and name his newborn son by Walda as the new heir to House Bolton instead. He then proceeds to commit kinslaying a second time by turning his hunting dogs on his stepmother Walda and his own newborn half-brother, as Walda pleaded for mercy.
- Euron Greyjoy, who murders his brother, Balon Greyjoy, by throwing him off a rope bridge at Pyke in the middle of a storm.
- Cersei Lannister, who orchestrated the Destruction of the Great Sept of Baelor which killed her uncle Ser Kevan Lannister, her cousin Lancel, and, less egregiously, her daughter-in-law Margaery Tyrell.
Alleged and Suspected Kinslayings
- Ser Gregor Clegane, suspected to have murdered his younger sister as well as his father.
- Domeric Bolton, trueborn son of Roose Bolton, is suspected of having been murdered by his bastard half-brother Ramsay Snow, in order for the latter to further his position in House Bolton (Ramsay's murders of his father, stepmother and his newborn half brother makes the true nature of Domeric's death more apparent).
- King Joffrey Baratheon, believed by most to have been poisoned by his uncle Tyrion Lannister at his own wedding. The actual killer is Olenna Tyrell, with help from Petyr Baelish and Dontos Hollard.
- Viserys Targaryen threatened to kill his unborn nephew Rhaego in a futile attempt to force his brother-in-law Khal Drogo help him take back the Iron Throne, which instead led to his own death by Drogo.
- Randyll Tarly felt that his eldest son and heir Samwell was a fat and bookish boy, utterly unworthy of the martial traditions of his family, or to lead House Tarly, so he sought to disinherit him. Randyll took Sam riding, and bluntly warned Sam to announce his intention to join the Night's Watch and forswear all right to inheritance. If Sam did not comply, he would take Sam out on a "hunting trip" and kill his own son in such a way that it looked like an accident. The terrified Sam subsequently joined the Watch.
- Tywin Lannister said that after Tyrion's mother, Joanna Lannister, died giving birth to him, he wanted to throw him into the ocean in his grief. Ultimately he didn't, however, because Tyrion was a Lannister.
- Cersei Lannister sat upon the vacant Iron Throne during the Battle of the Blackwater, while holding Tommen. Earlier she obtained the highly potent Essence of Nightshade from Pycelle, and intended to kill her son out of mercy should the battle be lost and Stannis' forces control King's Landing. She nearly followed through with her plan, but her father saved the day when he entered the moment Cersei was about to administer the poison to Tommen and declared that his army won the battle.
- During their travel to the Eyrie, after finding out that Arya Stark wanted his brother, Gregor Clegane dead, Sandor Clegane expressed his desire to kill his brother too.
- Jaime Lannister vows to kill his brother Tyrion Lannister for murdering their father Tywin.
- Roose Bolton explains to his bastard son Ramsay that he fathered him by brutally raping a miller's wife. The miller had married without his consent as his lord, so Roose hanged the miller and raped the miller's wife under the same tree that the miller hung from. The next year, she showed up at the Dreadfort with the infant Ramsay, and Roose nearly had Ramsay thrown into the river. When Ramsay suggests murdering Jon Snow to secure House Bolton's control of the North, Roose hints that he might kill Ramsay if he continued to be unpredictable and bloodthirsty. 
- Smalljon Umber makes a claim to Lord Ramsay Bolton that, had his own father not died on his own, he may have killed the Greatjon himself.
- Realising that her uncle Euron murdered her father Balon, Yara Greyjoy declared to all witnessed that once she won the Kingsmoot and the Salt Throne, her first order would be to execute Euron.
- Euron Greyjoy gives the order to have his niece and nephew, Yara and Theon Greyjoy, killed after he becomes the new King of the Iron Islands, but they flee the Iron Islands and take the Iron Fleet with them in anticipation of the danger.
- Rickard Karstark: "The blood of the First Men flows in my veins as much as yours, boy. I fought the Mad King for your father. I fought Joffrey for you. We are kin, Stark and Karstark."
- Robb Stark: "That didn't stop you from betraying me, and it won't save you now."
- Rickard Karstark: "I don't want it to save me. I want it to haunt you to the end of your days!"
- Robb Stark: "Kneel, my Lord. Rickard Karstark, Lord of Karhold, here in sight of Gods and men, I sentence you to die. Would you speak a final word?"
- Rickard Karstark: "Kill me and be cursed. You are no King of mine!"
- — Lord Rickard Karstark to King Robb Stark, his distant kin.[src]
- Davos Seaworth: "Forgive me, Your Grace, I'm not a learned man, but is there a difference between kill and sacrifice? The boy's your nephew."
- Stannis Baratheon: "What of it? We're at war. Why should I spare the son of some tavern slut Robert bedded one drunken night?"
- Davos Seaworth: "Because he has your blood in his veins."
- Stannis Baratheon: "So did Renly."
- Davos Seaworth: "Renly wronged you. Renly declared himself king when the throne belonged to you. He raised an army, stole your bannermen. This boy's done you no harm."
- — Davos Seaworth tries to dissuade Stannis from killing yet another member of his own family.[src]
- Tyrion Lannister: "What's the punishment for regicide? Drawing and quartering? Hanging? Breaking at the wheel?"
- Jaime Lannister: "Beheading."
- Tyrion Lannister: "Seems rather ordinary. And he was my nephew as well, so what's that? Fratricide is brothers, filicide is sons. Nepoticide! That's the one. Matricide, patricide, infanticide, suicide. There's no kind of killing that doesn't have its own word."
- Jaime Lannister: "Cousins."
- Tyrion Lannister: "Cousins? You're right. There is no word for cousin-killing! Well done."
- — Tyrion Lannister and Jaime Lannister discuss the various forms of familial killing.[src]
- "Tyrion may be a monster, but at least he killed our father on purpose. You killed him by mistake. With stupidity. You're a man of action, aren't you? When it occurs to you to do something, you do it. Never mind the consequences. Take a look. Look at the consequences. Here they are."
- ―Cersei Lannister to Jaime
- "He murdered my father. If I ever see him, I'll split him in two, and then I'll give him your regards."
- ―Jaime to Bronn
- "You want revenge against the Lannisters? I killed my mother, Joanna Lannister, on the day I was born. I killed my father, Tywin Lannister, with a bolt to the heart. I am the greatest Lannister killer of our time."
- ―Tyrion to Daenerys Targaryen
- Obara Sand: "We're not here to feed you, we're here to kill you."
- Nymeria Sand: "You want her to do it or me?"
- Trystane Martell: "We're family. I don't want to hurt you."
- — Obara and Nymeria Sand to Trystane Martell before they murder him.[src]
In the books
In the A Song of Ice and Fire novels, the taboo against kinslaying is pretty much the only reason that neither Tywin nor Tyrion ever try to kill Joffrey. Soon after Joffrey is crowned king it rapidly becomes apparent that he isn't simply vicious and cruel: he's a sadistic madman. Moreover, Joffrey is so utterly impulsive that he publicly, brazenly commits acts of petty cruelty that even the most ruthless kings of the past would have hesitated to commit, simply because it would be counter-productive. After Joffrey needlessly starts a city-wide riot, Bronn openly asks Tyrion why they don't simply assassinate Joffrey given that he causes far more problems than he solves, and moreover, actually has a pliable younger brother (Tommen) whom the Lannisters could easily use to replace him as their puppet king. Essentially the only reason Tyrion gives is that he won't kill his own nephew.
Characters in Westeros who have never met Daenerys Targaryen, as they start to hear news of her string of conquests in Slaver's Bay, are sometimes appalled to hear that her husband Drogo killed her own brother Viserys as she watched. This is largely because they didn't know how much of a monster he was, or that he violated Dothraki law by drawing a sword in Vaes Dothraki and threatening Drogo's unborn son, and thus Drogo was entirely within his rights to execute him. Then again, in these discussions other characters point out the well-known madness that runs in the Targaryen family, and accurately guess that Viserys may have been not much better than his crazed father King Aerys II Targaryen.
In the books Stannis Baratheon never admits that he ordered Melisandre to send the shadow demon against Renly, thus it is unclear if he is actually guilty of kinslaying.
Theon Greyjoy is sometimes inaccurately accused of being a kinslayer for his alleged execution of Bran and Rickon Stark, though as a highborn hostage and ward of the Starks he was not actually their blood relative. He is referred to as Theon Turncloak.
Ramsay Bolton is suspected of poisoning his trueborn half-brother Domeric Bolton to take his place as Roose's heir, and Roose confides to Theon that he believes Ramsay will kill any trueborn child Roose has in the future, as the taboo of kinslaying means nothing to him. Though Domeric is never mentioned on the television show, he is mentioned by Ramsay in "Iron From Ice", the first episode of Game of Thrones: A Telltale Games Series.
"Alton Lannister" in the TV series is a renamed version of Cleos Frey from the books. Cleos's mother Genna is actually Tywin's sister, making Cleos a first cousin to Jaime. The TV series apparently renamed Cleos for fear that the audience would be confused why a man named "Frey" was fighting for the Lannisters in Season 2 (before the Freys turn on Robb Stark in Season 3), so they renamed him as a Lannister to make clear what side he is on. Jaime didn't kill Cleos Frey in the books, rather he accompanied Brienne of Tarth on the mission to return Jaime to King's Landing for a prisoner exchange, but he was killed by outlaw bandits along the way. The TV series later made clear in "A Man Without Honor", however, that "Alton Lannister" isn't exactly the same character as Cleos Frey, but is instead a far more distant cousin. Jaime has difficulty even remembering who Cleos's mother is, and Alton says she is Cynda Lannister, not Jaime's well-known aunt Genna. So on the one hand, Jaime was never a kinslayer in the books but the TV series has him kill Alton. On the other hand, the TV series changed the relationship of "Alton Lannister" so he actually isn't a very close relative of Jaime at all - it is debatable how much the shame of kinslaying would apply to a fifth or sixth cousin. Moreover, it's vaguely implied that "Alton" was willing to give his life in a heroic escape attempt if it would free the famous Jaime (though he didn't understand that when Jaime said Alton wouldn't survive the escape attempt, he meant that he would kill Alton to distract the guard).
Killing a relative by marriage, instead of a blood relative, is still considered kinslaying, because in a spiritual sense they have become part of the same family. It's possible that it isn't considered quite as bad but only by a matter of degree, i.e. killing your own brother or son is generally seen as somewhat worse than killing your own brother-in-law, though both are still reviled. Lord Tytos Blackwood's son was killed at the Red Wedding, and he notes that one of Lord Walder Frey's wives was herself a Blackwood, but apparently the bonds of marriage mean nothing to Lord Walder. This wife was actually the mother of Lame Lothar Frey, meaning that Lame Lothar was responsible for the death of his kinsman Lucas Blackwood - given Lothar's club foot he might not have participated in the fighting directly, but he was one of the main masterminds who orchestrated the massacre and gave the orders. The exact relationship between Lame Lothar's Blackwood mother and the main Blackwood family hasn't been given, though the TV series might have condensed this. Just as kinslaying is considered a worse crime than regicide, violation of guest right is considered to be an even worse crime than kinslaying, so any kinslaying which occurred at the Red Wedding is overshadowed in the narrative by how outrageous and unthinkable it was that Lord Walder murdered guests under his own roof.
According to Ygritte, the gods hate kinslayers, even when they kill unknowing. She told Jon Snow a story about a wildling king named Bael the Bard, who kidnapped the daughter of one of the Stark lords. One day the daughter returned with an infant, who eventually became the new Lord Stark. Thirty years later, the son fought against Bael (unaware of their kinship) and killed him. Bael recognized his son and allowed him to kill him, for he could not shed the blood of his kin. When the Lord Stark returned from the battle and his mother saw Bael's head upon his spear, she threw herself from a tower in her grief. Her son did not long outlive her: one of his lords (presumably a Bolton) peeled the skin off him and wore it for a cloak.
George R.R. Martin has said that there are considered to be different degrees of kinslaying, depending on the relationship and circumstances, though these may be unofficial. Degrees of kinship are taken into account: killing your sibling or parent are both reviled, and what is often thought of as "kinslaying", but killing a parent is considered the worse of the two. Killing an uncle or nephew is also viewed negatively (such as when Stannis pondered killing his bastard nephew Edric Storm, replaced with his other bastard nephew Gendry in the TV series). All of these variants are considered to be much worse than killing a distant cousin, though this is still frowned upon (Robert Baratheon killed Rhaegar Targaryen, even though they were second cousins, but Robert wasn't universally reviled for this). The aristocracy of the Seven Kingdoms is heavily intermarried and many succession wars centered around rival claims between different groups of distantly related relatives. Martin specifically explained that Rickard Karstark was "stretching" when he warned Robb Stark that if he executed him it would be considered kinslaying, given that the Karstarks branched off from the main Stark family around one thousand years ago.
Martin also said that the circumstances of kinslaying are weighed by degrees (perhaps unofficially). Personally killing your own kin (with a sword, arrow, poison, etc.) is reviled, and hiring an assassin to specifically kill your kin for you is nearly as detested. If two brothers are leading rival armies against each other in war (such as Stannis and Renly), there are several variable outcomes. If Renly had announced to his army that he would reward the man who killed Stannis, or gave standing orders that Stannis was not to be taken alive, it would be viewed very negatively, though not quite as much as if Renly personally killed Stannis. If Renly publicly announced strict orders that he wanted Stannis captured alive, but Stannis accidentally ended up getting killed in the battle anyway, it would not be seen as nearly so negative. If Renly attacked Stannis's army but did not think to give specific orders about whether he wanted Stannis taken alive or dead, it would be seen as morally falling somewhere between the two, because he should have given more specific orders if he was concerned about avoiding kinslaying.
Therefore, personally murdering your own parent is considered to be the absolute worst kind of kinslaying - such as when Tyrion confronted his father Tywin with a crossbow and shot him dead. Robb Stark would, objectively, not be greatly blamed for executing Rickard Karstark, because he was a very distant cousin, and rather than "murder" Robb was within his rights to execute him for treason - though he chose to formally carry out the sentence with his own sword in hand. 
- ↑ "Mhysa"
- ↑ "And Now His Watch is Ended"
- ↑ "The Night Lands"
- ↑ "The Ghost of Harrenhal".
- ↑ "The Dance of Dragons"
- ↑ "A Man Without Honor"
- ↑ "Kissed by Fire"
- ↑ "The Children"
- ↑ "Hardhome (episode)"
- ↑ "The Red Woman"
- ↑ "Home"
- ↑ "Home"
- ↑ "Cripples, Bastards, and Broken Things"
- ↑ "Blackwater"
- ↑ "Kill the Boy"
- ↑ Home
- ↑ "Book of the Stranger"
- ↑ "The Door"
- ↑ So Spake Martin: Kinslaying in Westeros.
- ↑ So Spake Martin: Kinslaying in Westeros.
- ↑ So Spake Martin: Kinslaying in Westeros.
Rebellion · Regicide · Treason · Violation of guest right