He was the fourth son of Charles-Armand de Gontaut, duc Biron, and Marie Antoinette, Duchess of Lauzun.
He fought in Italy (attack on the Milan castle, Tortona and the Battle of San Pietro).
In the War of the Austrian Succession, he participated in 1741 in the invasion of Moravia and the Siege of Prague, where he was badly wounded.
It is said that some of his men risked their lives to save his, when in 1770 Biron was caught in a stampede caused by fireworks.
In 1753, he bought the Hôtel Biron from Anne, Duchess of Maine, which still can be visited today as it houses the Musée Rodin.