Queen Urraca (c. 1078--1126), who ruled the Kingdom of Leon-Castilla (also known as Castille-Leon) in northern Spain from 1109 to 1126, was the only woman during the Spanish medieval era to rule in her own right. The failure of her political marriage, which had been designed to unite the kingdoms of Leon-Castilla and Aragon, ultimately led to a civil war.

Background

Between 985 and 1002, the armies of the Muslim Caliphate of Cordoba repeatedly defeated the Christian armies of northern Spain. But with the death of the Muslim dictator's son and successor in 1008, the Cordoban caliphate began to collapse. With the fall of the caliphate, the dynasties of northern Spain began to rebuild themselves.

But fighting ensued between the Spanish provinces of Leon, Castilla, and Navarra. The Navarrese king eventually took control of both Castilla and Leon---the largest of the northern Christian states---giving rise to a new kingdom under the rule of...