Claude de Razilly fought in the Siege of Saint-Martin-de-Ré (1627) in 1627 and the Siege of La Rochelle.
In 1627, he successfully relieved the siege of the Royal forces in the fortress of Saint-Martin-de-Ré by sailing through an important English naval blockade.
In 1632, he was given by Richelieu in association with his brother Isaac de Razilly a mission to recover Acadia from the English following the Treaty of Saint-Germain.
He was Governor of Acadia when Port Royal was recovered in 1634.
[4] In 1638, Claude de Razilly fought in the Battle of Guetaria.