Duncan Targaryen was a son of Aegon V Targaryen. Prince Duncan was sometimes known as Duncan the Small, a reference to his namesake, Ser Duncan the Tall, who was Lord Commander of the Kingsguard for Aegon V. He fought Ser Barristan Selmy at a tournament in King's Landing when Barriston was only ten years old and was fighting in the tourney as a mystery knight. He also gave Selmy the nickname "The Bold." Ser Barristan later defeated him in a tourney. He died at the Tragedy of Summerhall along with his father and Ser Duncan the Tall.