Charles, like his father, made his early career in Brandenburg, attaining the rank of lieutenant-general in 1689.
In 1688, he served with his father as a mercenary of the Dutch Republic in the Glorious Revolution which made William III of Orange king of England in 1689.
From 1691 he served as "General of the troops of his British Majesty in Piedmont", during the Nine Years' War; commanding three regiments of exiled French Huguenots serving in the army of the Duke of Savoy: the regiments of Montauban, Miremont, and Montbrun.
[1] In late 1692, while still serving as General of the British troops in Piedmont, he was also appointed colonel of the Regiment Saint-Julian, whose commander, the Sieur Saint-Julian, had returned to French service after converting to Catholicism.
He was succeeded as Colonel of his Regiment by another Huguenot in British service, Henri de Massue, 1st Viscount (later 1st Earl) of Galway.