A knight of an important Galician noble family with strong ties in the region: the Moscosos. He held the position of Pertigueiro Maior of Terra de Santiago and was one of the leaders of the rebellion in Santiago against Archbishop Rodrigo de Luna, during the first siege of A Rocha.
Later he imprisoned Alonso II de Fonseca, who succeeded Rodrigo de Luna as archbishop, at the castle of Vimianzo.