Duncan Targaryen, known as the Prince of Dragonflies or Duncan the Lesser, was the eldest son of Aegon V Targaryen and Betha Nerbosc.
He became Prince of Peyredragon and heir to the Iron Throne when his father became King of the Seven Crowns, but he renounced his title and rights for the love of a peasant girl, Jenny of Old Stone, whom he married.
He shared the stubborn temperament of both his parents.
In the year 237, Duncan Targaryen was promised in marriage to a daughter of Lord Lyonel Baratheon of Accalmie. However, two years later, during a visit to the Conflans, he falls in love with a certain Jenny of Old Stone, whose origins are uncertain. Breaking his engagement, he marries Jenny. His father, Aegon V Targaryen, asks him to renounce this marriage and to dismiss Jenny, but Duncan persists.
The High Septon, the Grand Maester and the small council insist that Aegon V force his son to choose between his rights to the Iron Throne and his marriage. Prince Duncan chooses to renounce his rights and his title of Prince of Peyredragon in favor of his younger son Jaehaerys.
Outraged, Lyonel Baratheon entered into a short-lived rebellion against the Targaryens, which ended with the betrothal of his heir Ormund Baratheon to Duncan's youngest daughter, Rhaelle Targaryen. Although he has lost his claim to the throne, Duncan remains at court with his wife, Lady Jenny. His choice earned him the nickname Prince of the Dragonflies.
In the year 248, in Havrenoir, Prince Duncan participated in the jousts. He accepts to face a young mystery knight, whom he defeats. His opponent turns out to be Barristan Selmy, who participates anonymously when he is only ten years old and has not hesitated to challenge a Targaryen prince, thus earning his nickname "Bold". Barristan defeated Prince Duncan six years later at the winter tournament in King's Landing.
In the year 258, Duncan Targaryen learns that a group of mercenaries and outlaws called the Nine have gathered in the Dispute Lands, with the goal of offering a kingdom to each of its members. He commented on this news by stating that crowns were being sold at nine for a penny, and this comment became famous in the Seven Crowns, earning the conspirators the nickname Ninepenny Kings.
In the year 259, Prince Duncan died in the tragedy of Lestival, as did his father, Ser Duncan the Great and part of the court.
