The outbreak of the War of the American Independence caused relations between France and Great Britain to deteriorate.

After signing a formal treaty with the United States in February 1778, France broke diplomatic ties and declared war on Britain on 16 March 1778.

[3] Ligondès succeeded in turning the same broadside to both his assailants, putting Medea out of action with a shot below the water line after the first half-hour of the fight, but he was wounded in both arms soon afterward and had to hand over the command to Lieutenant de Roquart.

Medea retreated from the action; Triton and Jupiter continued to exchange fire for more two hours, until a squall of wind and rain, and the impenetrable darkness of the night separated the combatants.

[5] Jupiter had to sail back into Lisbon for refit with three killed and seven wounded.