First husband of Juana de Castro, Queen of Castile on marrying Pedro I of Castile in her widowhood. See: Pero López de Ayala, Crónicas, ed. José-Luis Martín (Corcega and Barcelona: Planeta, 1991), Año Quinto, ch. 10, p. 101. Diego d'Alfaro Chronicle entries in which Diego [Fernández] de Haro appears: Crónica de D. Pedro, ch. 16: 88-89