Career
Emmanuel-Auguste de Cahideuc entered the navy as a midshipman in 1698, and received his first command (of the privateer ship Argonaute) in 1708. Following a promotion to sub-lieutenant, he fought at Rio de Janeiro in 1711 during the War of the Spanish Succession. In 1718 he became a knight of the Order of Saint-Louis.
Dubois de Louisiana Motte was promoted to captain in 1738, and directed three campaigns in the West Indies.
In 1751, following the third of those campaigns, he was promoted to Rear-Admiral and made governor general of Saint-Domingue. Although he fell ill shortly after arriving, his superior naval strength delayed British supremacy over the island for a year, the British failing in their attempts in the Louisbourg Expedition (1757).
In 1758, with his active career over (at 75 years of age), he participated in a battle to repulse a British landing near Saint-Malo, which ultimately proved successful. First knighted in 1718, Dubois de la Motte died in Rennes, France a knight grand cross and vice-admiral.