Alfonso VII of Castile (March 1, 1104/5 – August 21, 1157), nicknamed the Emperor, became the king of Castile and Leon in 1126. He was the son of Urraca of Castile and Count Raymond of Burgundy.

Alfonso was a dignified and somewhat enigmatic figure. A vague tradition had always assigned the title of emperor to the sovereign who held León. Sancho the Great considered it the imperiale culmen and minted coins with the inscription Imperator Totius Hispaniae once crowned there. This sovereign was considered the most direct representative of the Visigoth kings, who were themselves the representatives of the Roman empire. But though given in charters, and claimed by Alfonso VI of Castile and Alfonso I of Aragon, the title had been little more than a flourish of rhetoric.

In November 1128 he married Berenguela of Barcelona, daughter of Ramon Berenguer III, Count of Barcelona. She died in 1149; their children were:
1. Sancho III of Castile (1134-1158)
2. Ferdinand II of Leon (1137-1188)
3. Sancha (1137-1179), married Sancho VI of Navarre
4. Constanza (1141-1160), married Louis VII of France

Alfonso remarried in 1152 to Richeza of Poland, the daughter of Wladislaus II the Exile of Poland. Their daughter was Sancha (1155-1208), the wife of Alfonso II of Aragon. By his mistress, an Asturian noblewoman named Guntroda, he had an illegitimate daughter, Urraca, who married Garcia IV of Navarre.

In Leon, Alfonso VII was crowned "Emperor of all Spain" in 1135 after the death of Alfonso I. The weakness of Aragon enabled him to make his superiority effective. He appears to have striven for the formation of a national unity, which Spain had never possessed since the fall of the Visigoth kingdom. The elements he had to deal with could not be welded together.

Alfonso was at once a patron of the church, and a protector if not a supporter of the Muslims, who formed a large part of his subjects. His reign ended in an unsuccessful campaign against the rising power of the Almohades. Though he was not actually defeated, his death in the pass of Muradel in the Sierra Morena, while on his way back to Toledo, occurred in circumstances which showed that no man could be what he claimed to be -- "king of the men of the two religions."