- (1333-1358) Son of Alfonso XI of Castile and his lover Leonor de Guzmán. Twin brother of the future Enrique II of Castile and half-brother of Pedro "the Cruel" of Castile.
- Master of the military Order of Santiago (1342-1358).
- Killed by his half-brother, Pedro King of Castile (1358).
- Lord of Haro and founder of the powerful lineage of the Enríquez, Admirals of Castile, which later received the title of Dukes of Medina de Rioseco.