Fernando de León

Fernando de León was the first son of Alfonso de León IX and the crown prince of León until his untimely death in 1214. He was the older brother of Sancha de León and Dulce de León and the older half-brother of Ferdinand de Castilla III and his siblings. His death, along with the death of his first cousin twice removed, Infante Henry de Castilla, led to a permanently united Castila & León under the rule of his half-brother, Ferdinand.