Second son of King Aegon II Targaryen and his sister Queen Helaena, born at King's Landing in 127 AC with a pale green dragon egg veined in silver laid in his cradle. He was two years old when the Dance came at his uncle Prince Lucerys's death over Shipbreaker Bay, and Prince Daemon Targaryen's reply that the blacks would have an eye for an eye, a son for a son was answered through the persons of Blood and Cheese, the rat-catcher and the sellsword who crept into the Tower of the Hand at dusk and caught his mother and her three small children visiting his grandmother. They named themselves debt-collectors come to be paid, and demanded Queen Helaena choose which of her two sons should die; when she named Maelor — as the youngest, who would not know what was happening to him — Cheese turned and told the babe his mother had given him over, and then Blood swung instead on Maelor's elder brother Prince Jaehaerys and took off his head with one cut, for the spite of the trick. The queen never recovered. She could not bear to look upon Maelor afterwards, and King Aegon took the boy from her and gave him to Queen Alicent to raise as her own.
When in 130 AC the city fell to Queen Rhaenyra and the king's children were sent away for safekeeping, Ser Rickard Thorne of the Kingsguard took Maelor disguised as a smallfolk's son in his arms and rode for Oldtown by the kingsroad. The two of them came at sundown to a flea-bitten inn at the blacks-held town of Bitterbridge called the Hog's Head, where the innkeep took a silver stag for leave to sleep in the stables. There the stableboy Sly, going through Ser Rickard's gear in search of more, found the prince's green dragon egg wrapped in a white cloak. Ser Rickard cut down the innkeep on the way out the door and ran with the boy across the town's stone bridge with a mob howling at his heels, until crossbowmen on the parapet brought him down with quarrels through his back; the washerwoman Willow Pound-Stone had to tear the screaming boy from his arms. The crowd then fell to quarrelling whether to carry the prince to King's Landing for Queen Rhaenyra's reward or south to the green camp at Longtable, and the prince was killed in the quarrel before Lady Caswell came down from her keep with her guards: Mushroom says Willow crushed him by accident in her grip, the Septon Eustace says a butcher chopped him in six pieces so each could have his share, and Grand Maester Munkun says the mob tore him apart with their hands. Lady Caswell hanged those she could catch, sent his head back to King's Landing and his egg on to Lord Ormund, and so closed the second of the three small lives Blood and Cheese had been paid to take.