She took part in most of the engagements of the European theatre of the Anglo-French War, notably the Battle of Ushant in 1778, where she served as Orvilliers' flagship, with Parscau du Plessix as flag captain. She took part in the Armada of 1779, but an epidemic aboard forced her to return to Brest in September. In 1779, her armament was reinforced by adding 10 further 6-pounders to her quarterdeck, turning her into a 110-gun. On 2 September 1780, "Bretagne" left Brest for Cadiz, where she took part in the Great Siege of Gibraltar.