As Exelmans' dragoons had already gained touch of the III.
Joining the 15th Light Dragoons in 1793, he became captain in the following year, and received a majority after serving as aide-de-camp to the duke of York in the Dutch expedition of 1799.
In 1811, along with the 3rd Dragoon Guards, the 4th Light Dragoons fought a notable cavalry action at Usagre, and in 1812 Lord Edward Somerset was engaged in the great charge of Le Marchant's heavy cavalry at Salamanca.
In 1756 he went to Canada as captain of dragoons and aide-de-camp to the marquis de Montcalm; and having distinguished himself in the war against England, was rewarded with the rank of colonel and the cross of St Louis.
He was anxious for a military career, and his name was placed upon the list of the 3rd Dragoons, then serving in India.