In need of major repairs by early 1755, she was not employed throughout the Seven Years' War, after which she was formally taken out of service on 17 March 1764 and was rebuilt by Joseph-Louis Ollivier at Brest from January to December 1765 as a Citoyen-class 74-gun ship of the line of the French Navy.

In 1778, Conquérant was under Baron de Monteil, part of the Third division in the Blue squadron of the fleet under Orvilliers.

[2] On 2 May 1780,[3] she departed Brest with the 7-ship and 3-frigate Expédition Particulière under Admiral Ternay, escorting 36 transports carrying troops to support the Continental Army in the War of American Independence.

The squadron comprised the 80-gun Duc de Bourgogne, under Ternay d'Arsac (admiral) and Médine (flag captain); the 74-gun Neptune, under Sochet Des Touches, and Conquérant, under La Grandière; and the 64-gun Provence under Lombard, Ardent under Bernard de Marigny, Jason under La Clocheterie and Éveillé under Le Gardeur de Tilly, and the frigates Surveillante under Villeneuve Cillart, Amazone under La Pérouse, and Bellone.

Immobilised, hopelessly overgunned and undermanned, her captain mortally wounded, Conquérant struck her colours and was seized by a boarding party from Audacious.