He decreed the establishment of the church at the Castrojeriz School (). The scholars Marcus B. Burke, Peter Cherry called him "an important minister of the reign of Philip III". He died 24 February 1628. His wife was María de Velasco and his daughter was Ana María de Mendoza. The bodies of him, his wife, and his daughter were taken to a church at the Convento de Las Descalzas Reales, Valladolid on 25 February 1628 to be subsequently moved to the church at the Castrojeriz School.
