Aegon IV Targaryen, King of the Seven Kingdoms

From Asoiaf

Aegon IV of House Targaryen, King of the Seven Kingdoms (reigned 172 AL - 184 AL), called the Unworthy, was the oldest son of Viserys II Targaryen, King of the Seven Kingdoms.

Aegon IV succeeded his father on the throne.

He was wed to Queen Naerys Targaryen. They had a son, Daeron II. It is rumored that Aemon the Dragonknight, Aegon's brother, was the lover of Queen Naerys, so Daeron might have been his son.

On Aegon's death Daeron II became king.