- "House Clegane was built upon dead children. I saw them lay Prince Aegon and Princess Rhaenys before the Iron Throne."
- ―Thoros of Myr
Princess Rhaenys Targaryen is an unseen character in Game of Thrones. She is deceased when the events of the series begin and she is not expected to appear in the series.
Rhaenys Targaryen was the daughter of Prince Rhaegar Targaryen and Princess Elia Martell. She had a younger full-brother, Aegon, and a younger paternal half-brother, Jon Snow. For mysterious reasons, Rhaegar allegedly abducted Jon's mother Lyanna Stark, sparking a Rebellion that ultimately deposed House Targaryen as the ruling house of Westeros. Rhaegar was killed by Robert Baratheon, who was Lyanna's betrothed, at the Battle of the Trident. Soon afterwards, Rhaenys and Aegon were brutally murdered along with their mother by Ser Gregor Clegane during the Sack of King's Landing.
Rhaenys is mentioned many times, along with her mother and brother, by her maternal uncle Oberyn Martell, who makes it quite clear that he wants justice for their deaths. He gets his chance to confront Ser Gregor when Tyrion Lannister demands a trial by combat to prove his innocence in the death of his nephew, King Joffrey Baratheon. Oberyn volunteers to be Tyrion's champion after learning that Ser Gregor will be fighting for the crown.
As the two champions commence battle at the trial, Oberyn identifies himself to the Mountain as the brother of Elia and reminds his opponent of the crime he committed against House Martell, saying, "You raped my sister, you murdered her, you killed her children." Despite wearing light armor and drinking before their fight, Oberyn initially gains the upper hand and proceeds to slowly cut down the Mountain all the while shouting in an ever louder voice, "You raped her! You murdered her! You killed her children!" Thinking his opponent to be fully incapacitated, Oberyn again demands the Mountain confess his crime and reveal who gave him the order, pointing accusingly at the Mountain's liege lord Tywin Lannister. However, in his hubris Oberyn is unexpectedly caught off guard when the Mountain suddenly trips him up. Berserk with fury at nearly being killed by his opponent, the Mountain pins Oberyn to the ground and proceeds to gouge out his eyeballs, making him scream in agony, as he roars for all to hear, "Elia Martell! I killed her children! Then I raped her! Then I smashed her head...in like this!" He then crushes Oberyn's skull, effectively confirming the long-standing rumor of arguably his most infamous war crime.
In the books
In the A Song of Ice and Fire novels, Rhaenys is the daughter of Prince Rhaegar Targaryen and Elia Martell and died in the Sack of King's Landing. Varys talks about her with the imprisoned Eddard Stark as an example of how the innocent suffer in times of uprising. She was three or four years old when she died, and took after her mother in appearance with the classic Dornish features of black hair, dark eyes, and olive skin.
Rhaenys had a small black kitten she named "Balerion", after the mighty dragon of Aegon the Conqueror. Varys commented about it sadly, "Rhaenys liked to pretend he was the true Balerion, the Black Dread of old, but I imagine the Lannisters taught her the difference between a kitten and a dragon quick enough, the day they broke down her door." No one knows what happened to the cat after she died: it is implied that it survived the downfall of the Targaryens and lived out the next fifteen years in the Red Keep during the reign of Robert Baratheon. When Arya Stark is ordered by Syrio Forel to chase cats around the Red Keep to train her in agility (which occurs in the TV series in "Cripples, Bastards and Broken Things") one of the cats she encounters is an incredibly old black cat with a chewed ear, who is mean to the entire Baratheon household, as well as the Lannisters. Once, when Tywin Lannister was visiting the Red Keep for a feast, the black cat jumped onto the table and snatched a roast quail right out of Tywin's fingers. According to Cersei, that cat attacks ravens at the rookery, and once clawed Joffrey's hand. This may very well be Rhaenys's cat Balerion, angered at the new residents of the castle who are responsible for the death of his original owner.
After King's Landing was seized by the Lannister forces, Rhaenys was found by Ser Amory Lorch hiding under the bed of her father Rhaegar. While Gregor Clegane killed her mother and brother, Lorch killed Rhaenys by stabbing her about fifty times. When Robert arrived in the capital her body was presented at his feet, and it looked nearly hacked to pieces. Even Tywin considered that deed overly brutal (not the murder itself, but the manner in which it was done). He asked Lorch why killing a two or three year old girl required so many thrusts, and Lorch answered that she kicked him and would not stop screaming. Tywin commented that if Lorch had half the brain a turnip has, he would have calmed Rhaenys with a few sweet words and used a soft silk pillow to smother her.
The TV series simplified events so that Gregor Clegane killed both of Elia's children, without the involvement of Amory Lorch.