In 1751 at the age of 16 Martin decided to seek his fortune abroad, and he signed up with the French Compagnie des Indes. His mother is reported to have said that he should not return from enlisting as a soldier until he was "in a carriage". He was posted to India where he served under Commander and Governor Joseph François Dupleix and General Thomas Arthur Lally in the Carnatic Wars against the British East India Company. When the French lost their colony of Pondichéry in 1761, he accepted service in the Bengal Army of the East India Company in 1763, ultimately rising to the rank of Major General.