Portuguese conquest of French Guiana

Invasion of Cayenne
Part of the Napoleonic Wars
Map of the Cayenne and the surrounding coastline, made in 1763
Date 6–14 January 1809 Location Cayenne, French Guiana Result Anglo-Portuguese victory Occupation of French Guiana by Portugal until 1817.
Belligerents
Portugal Brazil  United Kingdom	France
Commanders and leaders
James Lucas Yeo Manuel Marques de Elva	Victor Hugues
Strength
Portuguese forces: • Colonial Army of Brazil: 2,700 • Royal Brigade of the Navy (Portuguese Marines): 550 • Portuguese Colonial Navy of Brazil: brig Voador, brig Infante Dom Pedro, schooner General Magalhães, cutter Vingança and cutter Leão British forces: • Royal Navy: support from sailors & Marines of the frigate HMS Confiance	• Regular Army: 450 • Militia: 800
Casualties and losses
Portuguese: 1 killed 8 wounded. British: 1 killed. 23 wounded	16 killed. 20 wounded. Garrison, guns & stores all captured.

Anglo-Portuguese victory

Portugal

The Portuguese conquest of French Guiana was an 1809 military operation against Cayenne, capital of the South American colony of French Guiana, in the scope of the Napoleonic Wars. The operation was performed by a combined expeditionary force that included Portuguese (from Portugal and from Colonial Brazil) and British military contingents.

The operation was part of a series of attacks on French held territory in the Americas during 1809 and due to commitments elsewhere, the British Royal Navy was unable to send substantial forces to attack the fortified river port. Instead, appeals were made to the Portuguese government, which had been driven out of Portugal the year before during the Peninsula War and was resident in Brazil. In exchange for providing troops and transports for the operation, the Portuguese were promised Guiana as an expansion of their holdings in Brazil for the duration of the conflict.

The British contribution was small, consisting solely of the minor warship HMS Confiance. Confiance however had a highly effective crew and an experienced captain in James Lucas Yeo, who was to command the entire expedition. The more substantial Portuguese contingent consisted of 700 regular soldiers of the colonial Army of Brazil - led by Lieutenant Colonel Manuel Marques de Elva Portugal -, 550 marines of the Royal Brigade of the Navy detached in Brazil and several warships to act as transports and provide offshore artillery support. The French defenders were weakened by years of Royal Navy blockade and could only muster 400 regular infantry and 800 unreliable militia, formed in part from the territory's free black population. As a result, resistance was inconsistent and despite Cayenne's strong fortifications, the territory fell within a week.

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