Pedro González de Mendoza (3 May 1428 – 11 January 1495) was a Spanish cardinal, statesman and lawyer. He served on the council of King Enrique IV of Castile and in 1467 fought for him at the Second Battle of Olmedo. In 1468 he was named bishop of Sigüenza and in 1473 he became cardinal and archbishop of Seville and appointed chancellor of Castile. In the subsequent succession dispute, Mendoza supported Isabel's right to succeed her brother, Enrique IV, and participated in the battle of Toro, where the forces of Ferdinand and Isabella defeated the supporters of Juana la Beltraneja. Mendoza's Castilian chancellorship was reconfirmed by Isabel, and in 1482 he became cardinal-archbishop of Toledo and primate of Spain. He presided over the royal council for 20 years and his influence was such that he was called "the Third King" during the reign of Isabel and Fernando. Biography Pedro González de Mendoza was born on 3 May 1428 at Guadalajara in New Castile. He was the fifth son of Íñigo López de Mendoza and Catalina Suarez de Figueroa. The Mendoza family was the most powerful noble family in Spain at the time. González de Mendoza remained in Guadalajara until 1442 when he was sent to Toledo to continue his education under the auspices of Archbishop Gutierre Álvarez de Toledo. In Toledo he studied rhetoric, history and Latin. While still a teenager he was granted several ecclesiastical benefits, including the parish of Santa María in the town of Hita and the archdeacon of Guadalajara. When the archbishop died in 1446, he moved to the University of Salamanca, where he studied civil and canon law and earned doctorates in both by 1452. In 1452 he joined the court of Juan II of Castile as a member of the Royal Chapel. As a result of his influential family and status as chaplain to the king, Mendoza was soon appointed to his first bishopric: in 1453 he was selected by Juan II to become Bishop of Calahorra. The pope later confirmed his election and Mendoza was consecrated in 1454 by Alfonso Carrillo de Acuña, the Archbishop of Toledo. As bishop of Calahorra he was also señor, or civil and military ruler, of the town and its dependent district. In his secular capacity he led the levies of Calahorra in the civil wars of the reign of Henry IV. He fought for the king at