Jon was not entirely innocent of the history of the realm; his own maester had seen to that. “That was the year of the Great Council,” he said. “The lords passed over Prince Aerion’s infant son and Prince Daeron’s daughter and gave the crown to Aegon.”
“Yes and no. First they offered it, quietly, to Aemon. And quietly he refused. The gods meant for him to serve, not to rule, he told them. He had sworn a vow and would not break it, though the High Septon himself offered to absolve him. Well, no sane man wanted any blood of Aerion’s on the throne, and Daeron’s girl was a lackwit besides being female, so they had no choice but to turn to Aemon’s younger brother—Aegon, the Fifth of His Name. Aegon the Unlikely, they called him, born the fourth son of a fourth son. Aemon knew, and rightly, that if he remained at court those who disliked his brother’s rule would seek to use him, so he came to the Wall. And here he has remained, while his brother and his brother’s son and his son each reigned and died in turn, until Jaime Lannister put an end to the reign of dragonkings"