Spain enters the War
Impressed by the French victories against the British in America and the Mediterranean, King Ferdinand VI begins mulling entering the war against Great Britain. The French ambassador promised Minorca to Spain in return for Spanish assistance, and the return of the island had been one of Spain's primary goals.
Following the War of Jenkins Ear in 1748, King Ferdinand VI presided over a period of reform designed to strengthen Spain's navy and finances. In 1752, Spain signed the Treaty of Aranjuez with Austria, relinquishing dynastic claims in Italy once and for all. Free of dynastic entanglements on the continent, Spain was finally able to focus on strengthening her vast American empire. To that end, the Spanish government had turned its attention to reform and strengthening the Spanish navy. The result was that by 1757, Spain had a formidable force of 56 ships of the line, making the Spanish navy the third largest in the world, just behind Britain and France.
Throughout the decade, conflict with the British had been smoldering, due to British logging operations in Central America and the seizures of Spanish merchant ships. In 1754, the pro-French Marquis de Ensenada who headed the ministries of war, marine and the Indies, encouraged colonial governors to retaliate against British loggers in Labouring Creeek. A Spanish expedition was sent by the Governor of the Yucatan. However, the issue was resolved diplomatically, as Britain hoped to maintain Spanish neutrality.
By 1756, the situation had changed dramatically in France's favour and negotiations between Paris and Madrid throughout the winter of 1756-1757. On 15 April 1757, Spain formally declared war of Great Britain, the pretext being British incursions into Spanish central America.
To that end, the government of New Spain had been informed to remove British settlements from Central America. These operations had begun in March, and within a few weeks the British had been expelled.
On 20 April 1757 a French fleet of 14 ships of the line arrived at Cadiz from Toulon, along with a force of 8,000 men and several frigates to begin planning a joint assault on Gibraltar.
In 1757, Gibraltar is defended by a small garrison of fewer than 3,000 men defended the colony with a small fleet. Fearing Spanish entry into the war, there had been plans to reinforce the colony with two companies of artillery, however these were only meant to arrive in September. Also, a fleet of 12 British ships of the line were based in Gibraltar.
To begin the assault, throughout April and May, a series of fortifications and batteries were constructed by French engineers around Gibraltar, and a naval force surrounded the peninsula. The first Spanish assault on 14 May was repulsed by the British forces, with over 300 Spanish casualties. A relief force was assembled in Portsmouth with 14 more ships of the line, however the shortage of men delayed it sailing until June. Meanwhile, a barrage of constant artillery fire continued to rain down on Gibraltar.
Short on provisions, the discontent of the British soldiers in Gibraltar reached a boiling point by early June. A plot involving hundreds of regulars in two regiments had planned to seize the military chest of the colony from their officers and secure their escape by surrendering the fortress to the Spaniards. Over 700 men were involved and punished, further reducing the defences of the colony.
On 14 June 1757 a fleet of 34 French and Spanish ships of the line along with 8 frigates began firing on the British fortifications located between the old mole and new mole. British ships began firing back, and 4 Spanish ships were badly damaged with 2 French were rendered defenseless. Meanwhile, heavy artillery from La Linea began to shell the northern defences of the colony and the town itself.
Having lost over 500 men and with a force of fewer than 1,500 remaining, the Earl of Home surrender the fort to the Spanish forces on 17 June 1757. The colony was surrendered with honours of war and the remaining British fleet departed to defend the British Isles.
The reaction in Britain was one of immediate shock. With few soldiers to spare, Pitt would have a difficult time to reinforce what remained of British America. Therefore, most of the British fleet was recalled to defend the British Isles from a Franco-Spanish invasion.
In the meantime, the Spanish begin preparing an attack on Jamaica, and a joint Franco-Spanish invasion of Great Britain, to place the Stuarts on the British throne.
View of the Battle of Gibraltar 1757