Alfonso X (also occasionally
Alphonso X,
Alphonse X, or
Alfons X, 23 November 1221 – 4 April 1284), called
the Wise , was the
King of Castile,
León and
Galicia from 30 May 1252 until his death. During the
Imperial election of 1257, a dissident faction chose him to be
King of the Romans (; ) on 1 April. He renounced his imperial claim in 1275, and in creating an alliance with
England in 1254 his claim on
Gascony also.