He is member of a famous family of the Isle de France that includes scientists and soldiers.
On December 1, 1777, David Charpentier de Cossigny was lieutenant-colonel of the colonial regiment of the Isle of France.
In 1781, he was appointed to be part of the Indian expedition, under the orders of General Duchemin, commanding a detachment of 848 men from the Isle of France regiment, embarked and embarked himself on the squadron of which Le Bailli de Suffren took command after the death of the squadron chief of Orves.
On February 17, 1782, David Charpentier de Cossigny was on the ship the Sphinx, in naval combat that took place in front of Sadras.
His feats earned him the rank of colonel in 1784, before being appointed Governor of Pondicherry the same year.