The Battle of San Fernando de Omoa was a short siege and battle between British and Spanish forces fought not long after Spain entered the American Revolutionary War on the American side. On the 16 October 1779, following a brief attempt at siege, a force of 150 British soldiers and seamen assaulted and captured the fortifications at San Fernando de Omoa in the Captaincy General of Guatemala (now Honduras) on the Gulf of Honduras. The British forces managed to overwhelm and capture the Spanish garrison, consisting of 365 men. The British only held the fort until November 1779. They then withdrew the garrison, which tropical diseases had reduced, and which was under threat of a Spanish counter-attack. Background When Spain entered the American Revolutionary War in June 1779, both Great Britain and Spain had been planning for the possibility of hostilities for some time. King Carlos III set the defence of the Captaincy General of Guatemala as one of his highest priorities in the Americas, after the conquest of British West Florida. His forces seized the initiative in North America, where they rapidly captured the British outpost at Baton Rouge in September 1779, before the British were able to marshal any kind of significant defensive force in the area. The British sought to gain control over Spanish colonies in Central America, and their first target was San Fernando de Omoa, a fortress that Matías de Gálvez, the Captain General of Guatemala, called "the key and outer wall of the kingdom". However, the Spanish struck first. In September the capture of Cayo Cocina gave them possession of the British settlement at St. George's Caye (off the coast near present-day Belize City). Then, anticipating a British attack against the nearby port of Santo Tomás de Castilla, Gálvez withdrew the garrison there to Omoa. The Spanish had started building San Fernando de Omoa, principally with African slave labour, in the 1740s during the War of Jenkins' Ear. It became of the largest defensive fortifications in Central America, and one of the Guatemalan Captaincy General's principal Caribbean ports. British forces The decision by Gálvez to withdraw to Omoa upset British plans. Commodore John Luttrell, in command of three ships and 250 men, had intended an attack on the Santo Tómas, but his force was inadequate for an attack on Omoa. Even when he and Captain William Dalrymple arrived at Omoa on the 25 September