Second child and eldest son of King Aenys I Targaryen and Queen Alyssa Velaryon, born in 26 AC. He was on Dragonstone in 37 AC with his younger brother Viserys, listening to their grandsire tell tales of the Conquest, when Aegon the Dragon suffered the stroke that killed him. At fifteen he was lean and handsome and caught the eye of many a maiden, and was not indifferent to their charms; some said he was the very image of the Conqueror at the same age. Three years a squire, he improved greatly with sword and axe and was reckoned the best young lance in the realm, but he had claimed no dragon of his own, and his sister Rhaena had to take him up behind her on Dreamfyre if he wished to fly. In 41 AC his father wed him to that same elder sister and named him Prince of Dragonstone at the wedding feast, which so offended the Dowager Queen Visenya that she rose and left the hall. The Faith of the Seven was more offended still. The royal progress Aenys sent the pair on afterward went out with Rhaena forbidden her dragon, lest the lords and commons think the heir unmanly beside his wife, and it was jeered and pelted with dirt at every stop until the knights of the escort had to restrain Aegon from chastising the crowds. The High Septon soon after named Aenys a tyrant with no right to rule, and the Faith Militant rose.
In 42 AC the Poor Fellows had Aegon and Rhaena penned at Crakehall when word came that King Aenys had died on Dragonstone, and that Visenya had fetched Maegor home from his exile in Essos to take the crown. The couple slipped away to Casterly Rock, where Lord Lyman Lannister sheltered them under guest right and where their twin daughters Aerea and Rhaella were born late that same year. His friends fell away from him after Maegor's coronation, for it was whispered through the realm that Aegon was weak as his father had been, a prince who had never dared a dragon while his uncle rode Balerion the Black Dread. His mother Alyssa proclaimed him king regardless, and the name that stuck to him was Aegon the Uncrowned. In 43 AC, with Maegor away in Oldtown, he and Rhaena were smuggled through a gate of King's Landing in a mule wagon under sacks of corn, aided within the walls by men grown weary of the usurper's persecutions. They did not go for the Iron Throne, having no strength to hold it; they went for dragons. Rhaena took back Dreamfyre and Aegon claimed at last his dead father's mount Quicksilver, and the two of them flew out of the city to raise an army. The great lords of the Stark, Arryn, Baratheon, and Lannister houses answered his mother's letters but would declare for him only after a victory, and so he denounced his uncle as tyrant and usurper and marched fifteen thousand men through the riverlands with Quicksilver above them. Royalist armies converged on him from three directions, and rather than break them one at a time as a seasoned commander would have done, he waited. Maegor came upon him on Balerion in the sky above the Gods Eye, and the older and greater dragon killed both prince and mount together.