He practiced as a lawyer and became a cleric in Genoa. He later moved to Rome, becoming a Referendary of the Apostolic Signatura. On September 27, 1543, he became an abbreviator de parco maiori. He was made a secretary apostolic on December 1, 1551. The pope also made him a domestic prelate. On July 27, 1562, he became a member of the Apostolic Camera. He was made praefectus annonae on November 13, 1562. He accompanied Cardinal Carlo Carafa during his legation to Philip II of Spain.
On July 6, 1565, he was elected Bishop of Ventimiglia. He was transferred to the see of Luni-Sarzana on September 7, 1565. On the same day, he opted for the titular church of Santa Sabina. He was consecrated as a bishop by Cardinal Clemente d'Olera in San Pietro in Montorio on November 21, 1565.
He participated in the papal conclave of 1565-66 that elected Pope Pius V. The new pope named him papal legate in the Campagne and Maritime Province in 1571. On March 17, 1572, he was transferred to the see of Anagni. He participated in the papal conclave of 1572 that elected Pope Gregory XIII.
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