Already settled in Castile by around 1330 he appears often in charters confirming as the alférez of his cousin Alfonso XI and also as the tutor (ayo) and later mayordomo of Infante Pedro, who was barely fifteen years old when his father died, forming a close relationship with the young king as his favorite and one of the most influential politicians in the kingdom. He was also the chancellor of King Alfonso XI and during part of the reign of his son Peter I.
