Born in 42 AC at Casterly Rock — where her father Prince Aegon Targaryen and her mother Princess Rhaena had taken refuge from the Poor Fellows risen against the throne — and twin to her sister Rhaella, the silver-gold mirror image of her face. Within a year her father had been crushed in battle against his usurping uncle King Maegor I, and Rhaena had disguised her two girls and sent them away in secret with allies whose names she herself did not know. Tyanna of the Tower, the most cunning of King Maegor's queens, found the twins hidden at the keep where they had been kept; in 47 AC she used their captivity to bind Princess Rhaena into the third marriage of the Black Brides, and there the elder twin lived as the king's named heir at his court until Lord Rogar Baratheon raised her uncle Jaehaerys against him.
Some at Oldtown believed the bold girl who came back to King's Landing in Jaehaerys's train after his coronation was not the timid Aerea who had ridden south but her twin Rhaella, switched at the Starry Sept — and so it was that the same name reigned briefly under two faces for the early years of the new king's reign. She was named heir by Jaehaerys until his own children should come, was the target of a foiled plot of the Baratheons to make her queen, and was finally restored to her unknown mother on Dragonstone in 51 AC, where she found nothing she could love. She begged her one friend the seafarer Elissa Farman to take her west, raged at being displaced as heir by the newborn Princess Daenerys, called her mother's court ladies by names like Lady Farts-a-Lot and Ser Stupid, and at last in the closing days of 54 AC stole into the dragonmount and claimed the Black Dread Balerion — the great beast who had borne King Maegor — and was gone upon him into the east. A year and a half later, on the thirteenth day of the fourth moon of 56 AC, Balerion returned to King's Landing with a creature clinging to his back that was barely a girl: stick-thin, hair matted, eyes blood-red, dressed in tatters, the words I never the last words she would speak before she collapsed. Grand Maester Benifer and Septon Barth shut her into his chambers and turned away every other man, even the king. The princess was burning from within — her flesh dark as cracklings, smoke coming from her mouth and nose, swelling things moving beneath her skin — and when they lowered her into a tub of ice the things that came out of her, one as long as a man's arm and made of heat and fire, perished in the cold. Septon Barth wrote in his private papers that he prayed soon to forget the things she had whispered to him, and concluded it had been Balerion and not Aerea who had chosen their road: that the great dragon had gone home to the smoking ruins of Valyria, and brought back what he had found there in his rider's belly.