Jaehaerys II Targaryen, King of the Seven Kingdoms

From Asoiaf

Jaehaerys II of House Targaryen, King of the Seven Kingdoms (reigned 259 Al - 262 AL), was the second son of Aegon V Targaryen, King of the Seven Kingdoms.

He succeeded his father on the throne.

He had a single son, Aerys II, and a daughter, Rhaella.

On his death his son Aerys became king.