Dominica's defenses were threadbare. The entire British regular force numbered about 100 soldiers, scattered among the capital Roseau, the hills above it, and the fort at Cachacrou on the southern tip. Governor Thomas Shirley had been worried about the island's vulnerability since the American war began in 1775, pushing forward fortification improvements against instructions from London to minimize defense spending. He had good reason for concern: the British Leeward Islands fleet under Admiral Samuel Barrington was far more powerful than anything on the island, but Barrington was under orders to hold most of his ships at Barbados until receiving further instructions. A single ship of the line stationed at Dominica might have prevented what came next. None was there.

After sunset on September 6, a flotilla departed Martinique carrying 1,800 French troops and 1,000 volunteers aboard three frigates - the Tourterelle, Diligente, and Amphitrite - the corvette Etourdie, and a collection of smaller vessels. De Bouille divided his force with the precision of a man who had studied his target carefully. The main body of 1,400 landed about two miles south of Roseau near Pointe Michel. De Bouille himself came ashore at Loubiere with 600 men, between Pointe Michel and the capital. Another 500 landed north of Roseau, completing the encirclement. As troops moved to seize the high ground above the town, the frigates swung into position and began bombarding Roseau's meager coastal defenses.

By midday on September 7, French soldiers occupied the ridgelines overlooking Roseau. Stuart surveyed his situation and found it hopeless - outmanned, outgunned, surrounded on three sides with warships closing the fourth. He surrendered. De Bouille, shrewd enough to know that governing required goodwill, forbade his troops from plundering the town. Instead, he levied a fee of 4,400 pounds on the island's population, distributed among his men as compensation. The restraint was calculated: a sacked town breeds insurgency, while a taxed one might accept new management. News of Dominica's fall reached London with surprise and blame. Admiral Barrington bore the brunt of criticism for keeping his fleet anchored at Barbados, though he had been following orders.

Dominica's capture was the opening move in a series of Caribbean exchanges during the American Revolutionary War. Barrington, stung by the criticism, launched his own campaign in December 1778, taking the French island of St. Lucia. De Bouille remained a central figure throughout, eventually capturing the British surrender of Saint Kitts in 1782, where he took Governor Thomas Shirley - the same man who had tried to fortify Dominica years earlier - as his prisoner. But the 1783 Treaty of Paris returned Dominica to British control, much to de Bouille's frustration. The aftermath proved complicated in ways the treaty's signatories did not anticipate: France had armed local indigenous and mixed-heritage Dominicans during the invasion, and these communities, no longer willing to accept British expansion into their lands, resisted with a new confidence that led to further conflict by 1785.