Soldier. Served as lieutenant (1764) and captain (1766) of the militia at St.-Domingue. Went to France (1774-1777; 1779). Commanded a company of cavalry at St.- Domingue (1790). Visited the United States (1792-1793) and Jamaica (1795-1800). Served as captain of infantry under the Restoration.

Descendant of a noble family, British by origin, that had settled in St.-Domingue. Believed that his family was related to William Alexander, Lord Stirling.

Born at St.-Domingue. Younger brother of the marquis Hugues-Barthélemy Alexandre d’Hanache. Married in 1780 to Henriette Cochon du Puy.