Career
In 1445, Alonso de Fonseca y Ulloa was appointed by the King of Spain and confirmed by Pope Eugene IV as Bishop of Ávila. On 4 February 1454, he was appointed by Pope Nicholas V as Archbishop of Seville. In 1465, he was appointed by Pope Paul II as Archbishop of Santiago de Compostela.
In 1469, he was appointed by Pope Paul II to his prior position as Archbishop of Seville where he served until his death in 1473.
While bishop, he was the principal consecrator of Pedro González de Mendoza, Bishop of Calahorra y Louisiana Calzada (1454).