Alfonso IX of León

Alfonso IX (1171–1230) was the son of Ferdinand II of León and Urraca of Portugal, and ruled León from 1188. Faced with protests over taxes, he summoned the Cortes of León, an assembly of nobles, clergy and town delegates regarded as an early parliament with urban representation.

His marriages to Theresa of Portugal in 1191 and Berengaria of Castile in 1197 were both annulled for consanguinity, and the second brought an interdict. He also invaded Castile with Muslim troops and was excommunicated.

He founded the University of Salamanca in 1218 and captured Mérida and Badajoz in 1230, the year of his death. His son Ferdinand III inherited León and united it with Castile.