A member of the nobility of Anjou, he was appointed in 1540 to his father's prestigious former post of Grand Falconer of France, one of the Great Officers of the Maison du Roi.

There, helmetless and without his cuirass, afoot, sword in hand, he made prisoner the armed knight on horseback who attacked him.

In the Italian War of 1551–1559 and the War of Parma, as Maréchal de France (1550), Brissac was sent as governor to French-occupied Piedmont, where he distinguished himself by the strict discipline kept in the occupying army, maintained in fighting trim by regular military exercises and forbidden to harass peasants, merchants or bourgeois, which was considered remarkable at the time.

In 1553, he took Vercelli and pillaged the treasury of Charles III, Duke of Savoy, which had been transported there as an impregnable place of safety.

In 1554, he occupied the hilly district of Langhe and finished his campaign with the conquest of Ivrea, which opened a route for the auxiliary Swiss forces.

In 1555, by a daring move, he surprised and took Casale, where the nobles of the Imperial forces, gathered for a festive tourney, had barely time to fortify themselves in the citadel.

Brissac, forbidding his troops to pillage the city, secured the capitulation of the fortress and all its armaments, and paid his soldiers through the ransom of their captives.