The Invasion of Dominica (7 September 1778) was a successful French invasion of the island of Dominica in the British West Indies, during the American Revolutionary War. The action took place before British authorities in the Caribbean were aware that France had entered the war as an ally of the United States of America. The French governor in the West Indies, François Claude Amour, marquis de Bouillé, was notified on 17 August that France was at war, and organized the invasion, infiltrating spies to rally sympathetic French-speaking Dominican support.
Early on 7 September 1778, French forces landed on the southeastern coast of the island. They rapidly took over some of the island's defenses, and eventually gained control of the high ground overlooking the island's capital, Roseau. Lieutenant Governor William Stuart then surrendered the remaining forces. Dominica remained in French hands until the end of the war, when it was returned to British control.
Background
Following the pivotal Battles of Saratoga in October 1777 and the ensuing surrender of British General John Burgoyne's army, France decided to openly enter the American War of Independence as an ally of the young United States of America. France's objectives in entering the war included the recovery of territories that had been lost to Britain in the Seven Years' War. One key territory that was of particular interest was the West Indies island of Dominica, which lay between French-held Martinique and Guadeloupe, and had been captured by Britain in 1761. Recapture of the island would improve communication among the islands, and deny the use of Dominican ports to privateers who preyed on French shipping.
On Dominica, Governor Thomas Shirley had been concerned about the island's security since the war began in 1775. Operating against instructions from colonial authorities in London to minimize expenses for defence, he had pushed forward the improvement of a fort at Cachacrou and other sites. This work was incomplete when Shirley took leave in June 1778, sailing for England. Command was left with Lieutenant Governor William Stuart, and work to improve the defenses was still incomplete in August 1778, when François Claude Amour, marquis de Bouillé, the governor of the French West Indies, received word that war had been declared.
Prelude
The French frigate Concorde reached Martinique on 17 August with orders from Paris to take Dominica at the earliest opportunity, and de Bouillé made immediate plans for such an operation. He had maintained contacts in the Dominican population, which was dominated by ethnic French, including free people of color, during the years of British administration. As a result, he had an accurate picture of the condition of the Dominican defences, and knew that the island's garrison numbered fewer than "fifty soldiers fit for duty". He was also concerned with the whereabouts of the British Leeward Islands fleet of Admiral Samuel Barrington, which was significantly more powerful than his own. Unbeknownst to de Bouillé, Barrington, who had only recently assumed his post, was under orders to retain most of his fleet at Barbados until receiving further instructions. The British regular forces on the island, which in total numbered about 100, were distributed among defences in the capital Roseau, the hills that overlooked it, and at Cachacrou.
De Bouillé carefully maintained a facade of peace in his dealings with Dominican authorities while he began preparing his forces on Martinique. On 2 September he and Stuart signed an agreement that formally prohibited privateering crews from plundering. 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. On 5 September de Bouillé was informed that the frigate had sailed for Barbados.
He immediately acted to launch his invasion. Some Frenchmen (some British sources suggest they were French soldiers infiltrated onto the island) gained entry to the battery at Cachacrou that evening, plied its garrison with drink, and poured sand into the touchholes of the fort's cannons, temporarily rendering them useless. De Bouillé had infiltrated some agents onto the island who had convinced some of the local French-speaking militia to abandon their duties when called up.