Diego Lainez was a courtier, bureaucrat, and knight of the Kingdom of Castile and the lord of Vivar, six miles to the north of Burgos, Spain. Lainez was a veteran of many battles against the Moors, and he was a courtier in the service of King Sancho II of Castile, confirming one of his documents; he was formerly the champion of King Fernando I of Leon before Count Gormaz of Oviedo became the king's new champion. Diego's son Rodrigo Diaz de Vivar would be even more famous as "El Cid", and he would unite Christians and Muslims against the Almoravids of Valencia in 1099.