But the stone began to crack in 92 AC, when Aemon, Prince of Dragonstone, was slain on Tarth by a Myrish crossbow bolt loosed at the man beside him. The king and queen mourned his loss, and the realm with them, but no man was more bereft than Prince Baelon, who went at once to Tarth and avenged his brother by driving the Myrmen into the sea. On his return to King’s Landing, Baelon was hailed as a hero by cheering throngs, and embraced by his father the king, who named him Prince of Dragonstone and heir to the Iron Throne. It was a popular decree. The smallfolk loved Baelon the Brave, and the lords of the realm saw him as his brother’s obvious successor.
Fire and Blood, by George R.R. Martin, pg 340