- A knight at the service of Juan I of Castile.
- Juan I of Castile sent him, Juan Serrano, Prior of Guadalupe, and Álvaro Martínez de Villarreal, doctor in canon and civil law, with his reply to the Duke of Lancaster when the latter arrived in Galicia and sent the king a message claiming the crown of Castile for his wife and himself (1386).
- Bibl: M. D. J. M., Historia Del Reinado de D. Pedro Primero de Castilla (Sevilla: Cários Santigosa, 1847), p. 182.
Diogo Lopez de Mendrano
Chronicle entries in which Diego López de Medrano appears:
Crónica de D. João I, part 2, ch. 84