Guillén Pérez de Guzmán [SEP] father
Guillén Pérez de Guzmán
Guillén Pérez de Guzmán (ca. 1180–1233), a member of the House of Guzmán, one of the most aristocratic of the Kingdom of Castile, was the maternal grandfather of Queen Beatrice of Castile, Queen Consort of Portugal as the wife of King Alfonso III. His father was Pedro Rodríguez de Guzmán—killed in the Battle of Alarcos on July 18, 1195and son of Rodrigo Muñoz de Guzmán—and Mahalda With his brothers Nuño and Theobald, he fought alongside King Alfonso VIII at the decisive
Vasques de Soverosa, with issue. Guillén Pérez de Guzmán and his wife María were the parents of: 
- Nuño Guillén de Guzmán, married to Teresa Álvarez de Manzanedo
- Pedro Núñez de Guzmán, "adelantado mayor" of Castile and father of Alonso Pérez de Guzmán.
- Mayor Guillén de Guzmán, mistress of King Alfonso X of Castile with whom he had a daughter, Beatrice of Castile, the wife of King Afonso III of Portugal.