- (1341–1359) Son of Alfonso XI of Castile and his mistress Leonor Núñez de Guzmán.
- Killed in Carmona, at the age of nineteen, by order of his half-brother Pedro King of Castile in the course of his revenge against the Guzmán family. His brother Pedro Alfonso, aged fourteen, was also killed on the same occasion. [Pedro, ch. 25: 35-38]