The conflict, which took place in July–August 1762, began when William Lyttelton, the British governor and commander-in-chief of Jamaica, sent a naval expedition to Nicaragua with the primary objective of capturing the town of Granada.

The Fortress of the Immaculate Conception, which would be besieged by the British, is located on the southern side of the rive by the village of El Castillo in present day Nicaragua.

[7] Because it represented a potential route between the Atlantic and Pacific oceans, as well as the possibility of expanding their colonization of Central America beyond the Miskito Coast, Nicaragua was a major target of attacks by the British during the 18th century.

The Miskito Kingdom later aided Britain during the American Revolutionary War by attacking Spanish colonies and gained several victories alongside the British.

The goal was to sail up the San Juan River to Lake Nicaragua and capture the town of Granada, which would effectively cut Spanish America in half as well as provide potential access to the Pacific Ocean.

[13] The combined British and Miskito Sambu expeditionary force headed towards the Fortress of the Immaculate Conception on the San Juan River in July.

At 4 o'clock that morning, the lookout on duty heard cannon fire from the east, in the direction of an observation post located at the junction of the Bartola and San Juan rivers.

A few hours later, with his fleet anchored in the river, the British commander sent an envoy to demand the unconditional surrender of the fortress in exchange for avoiding further hostilities.

Animated by the spirit of her late father and ancestors and knowing the risk to her honor and virginity with the barbarity of the Miskito Sambu, she strongly opposed the fort's surrender.

[2] At nightfall, Herrera ordered the troops to throw some sheets soaked with alcohol into the river on floating branches and set them on fire.

[5][clarification needed] Inspired by Herrera's acts of heroism, Lieutenant Juan de Aguilar, the pro tempore garrison commander, led the defenders to victory in a battle that lasted six days.

[1][2][6] Herrera handled the cannons of the fortress, and the Spanish managed to defend the strategic position, but the British finally lifted their siege after being called for service in other more critical areas of the Seven Years' War on 3 August 1762.

Fortunately for the defenders of the fortress, Spain and Britain began peace negotiations (in Fontainebleau in November, the Spanish ceded Florida to the British.

After Spain entered the American Revolutionary War in 1779, Major General John Dalling, the British governor and commander-in-chief of Jamaica, proposed a second naval expedition to Nicaragua.