On 2 September he and Lieutenant Governor Stuart signed an agreement that formally prohibited privateering crews to plunder. The next day de Bouillé sent one of his officers to Dominica to see whether a Royal Navy frigate was still anchored in Prince Rupert's Bay (near present-day Portsmouth). Stuart, suspicious of the man, had him questioned and then released.[30] On 5 September de Bouillé was informed that the frigate had sailed for Barbados.[30] He struck fast, defeating the British at Dominica in September 1778.[27] De Bouillé left a garrison of 800 (700 French regulars and 100 free black militia) on the island, turned its command over to the Marquis de Duchilleau, and returned to Martinique.[33] These events were the first in a series of military actions resulting in the change of control of Caribbean islands during the war, in which De Bouillé was often involved.[34]