On 2 December 1802, she was renamed to Marengo, reflecting the political change away from the Revolutionary Republic inspired by Jean-Jacques Rousseau towards the advent of General Bonaparte.

On 6 March 1803, she departed Brest as the flagship of a squadron under Admiral Linois, set to take possession of Pondicherry, which the Treaty of Amiens had attributed to France.

War eventually broke out in September, and Linois reinforced French garrisons at La Réunion and Batavia, and then set out to prey upon British trade in the Indian Ocean.

The British commander, Commodore Dance, led a vigorous defence and Linois, feeling isolated away from supplies and repairs and unwilling to risk attrition, chose to withdraw.

The news of Linois' failure further discredited him at Batavia, and the growing reluctance of the Dutch to provide support to his squadron forced him to return to Isle de France.

[3] In March 1806, Linois set out to return to France with Marengo and Belle Poule, and prey upon British shipping between St. Helena and the Canary Islands on his way home.

In the ensuing Action of 13 March 1806, London engaged Marengo, which eventually struck her colours; Belle Poule battled against Amazon and later against Ramilles, and had to surrender as well.