Capture of St . Lucia The Capture of St Lucia or the Battle of Morne de la Vierge was a battle fought on the island of St . Lucia in the West Indies during the American War of Independence between 18 and 28 December 1778 , between British and French forces . The British landed on St . Lucia and defeated a French landing force that had come to reinforce the garrison . The island then capitulated . Background . On 7 September 1778 , the French governor of Martinique , the Marquis de Bouille , surprised and captured the British island of Dominica . On 4 November , French Admiral Jean Baptiste Charles Henri Hector Comte d ' Estaing sailed for the West Indies from the port of Boston . On that same day , Commodore William Hotham was dispatched from Sandy Hook , New York , to reinforce the British fleet in the West Indies . Hotham sailed with " five men of war , a bomb vessel , some frigates , and a large convoy . " The convoy Hotham was escorting consisted of 59 transports carrying 5 , 000 British soldiers under Major General Grant . The French fleet was blown off course by a violent storm , preventing it from arriving in the Caribbean ahead of the British . Admiral Samuel Barrington , the British naval commander stationed on the Leeward Islands , joined the newly arrived Commodore Hotham on 10 December at the island of Barbados . Grant ' s men were not permitted to disembark and spent the next several days aboard their transports . Barrington and Hotham sailed for the island of St . Lucia on the morning of 12 December . Invasion . On the evening of 13 December and morning of 14 December , Major General James Grant , supported by additional troops under Brigadier General William Medows and Brigadier General Robert Prescott , landed at Grand Cul de Sac , St . Lucia . Grant and Prescott took control of the high ground around the bay , while Medows continued on and took Vigie the following morning ( 14 December ) . Also on the same day the invaders marched upon the capital of Castries , and the fort of Morne Fortuné , which the French governor , Claude Anne Guy de Micoud , evacuated without a ﬁght . The French decided it best to retire into the jungle , allowing Grant to occupy the Carénage Bay , three miles north of Cul de Sac , without losses and by the evening of 14 December . That evening the French fleet under d ' Estaing arrived , forcing Admiral Barrington to move his ships into line of battle and abandon his plan to bring the transports into the bay . Battle of Morne de la Vierge . On 18 December 1778 , a force of 9 , 000 French troops was landed on St . Lucia . The small British force of 1 , 400 men occupied a hill located on the neck of a peninsula , known as Cul de Sac . The French were fairly raw soldiers , trained to fight in the classic European style of linear battles . They advanced on the British force several times . The British , particularly the 5th Regiment of Foot , were veterans of colonial fighting . They inflicted a stinging defeat on the French , who lost 400 killed and 1100 wounded ; British losses were only 10 killed and 130 wounded . With the defeat of d ' Estaing on 15 December and therefore the loss of all hope of reinforcement , the French garrison surrendered on 28 December . The imminent arrival of British reinforcements under John Byron forced the French to reembark their remaining troops during the night of 28 – 29 December , returning to Martinique by 30 December . Aftermath . St . Lucia became a crucial base for the British fleet for the rest of the war in the Lesser Antilles , providing a critical resupply point used in battles such as the crushing defeat of French naval power at the Battle of the Saintes in 1782 at the hands of Admiral Rodney . The British held the island until 3 January 1784 , providing a good bargaining chip during negotiations with the French over the fate of other islands seized from Britain during the war in the Caribbean , such as Dominica . After the battle , the 5th Foot took the white plumes worn by the French soldiers and wore them as battle trophies . Later on , these plumes became the standard part of the uniform for the regiment .