Chevert was born in Verdun, Meuse. He entered service in 1706, became major in Beauce's regiment in Toul in 1728, later in 1739 lieutenant-colonel. He distinguished himself in Flanders, Piemont and Germany and herefore rewarded by a more important command. He led the siege of Prague in the War of the Austrian Succession with his grenadiers in 1741 and defended the city against the Austrian troops. Named brigadier-general, he took part in the operations in the Dauphiné and Italy, most famously Casteldelfino, and became maréchal-de-camp in 1744.