Aegon V Targaryen, also called Aegon the Unlikely, and informally known as Egg, is an unseen character in Game of Thrones. He is long dead by the time the series begins. Aegon V was the fifth king of his name to sit on the Iron Throne and the fifteenth king of the Targaryen dynasty to rule the Seven Kingdoms. He was the father of the Mad King and his sister-wife Queen Rhaella; grandfather of Rhaegar, Viserys, and Daenerys Targaryen; great-grandfather of Jon Snow; and younger brother of Maester Aemon. In the books, he was dubbed "the Unlikely" because he was the fourth son of Maekar Targaryen, who was in turn the fourth son of Daeron II Targaryen, and thus Aegon was highly unlikely to have inherited the crown.