He attended University of Padua to study law.

As part of the French Army, he fought Calvinists in Languedoc under Henry II.

[1] His ecclesiastical career developed in France, first as abbot of Saint-Victor in Marseille (which he renounced in 1561), later as abbot of Villar San Costanzo at Staffarda, and then as bishop of Béziers in 1547.

His cousin Queen Catherine de' Medici convinced him to join the church.

He was made a cardinal by Pope Paul IV in the consistory of 15 March 1557, with the title of Santa Balbina.