The Treaty of Aranjuez between Spain and France was Signed in April 1779

The treaty of Aranjuez between Spain and France was signed in April 1779, fourteen months after France had declared war on Great Britain and entered the American War for Independence. Under the terms of the treaty, Spain entered the war as an ally of France in exchange for a French pledge to assist Spain in recovering Gibraltar, Minorca, and lost Spanish colonies in the Caribbean. The primary Spanish objective in the war was to eject the British from Gibraltar. In July 1779, Spanish land and naval forces commenced a siege and blockade of the 5000-man British garrison there.

By late 1779 British supplies in Gibraltar were running low. If not reprovisioned, the garrison would ultimately be forced to surrender. So, on December 29, 1779, a British fleet under the command of Admiral Sir George Rodney sailed from Portsmouth, with orders to break the Spanish blockade and resupply Gibraltar.

On January 8, off the coast of Portugal, Rodney’s fleet surprised seven Spanish warships escorting 15 ships carrying provisions and powder. Overwhelmed and outgunned, the Spanish surrendered after only token resistance. Rodney sent the captured powder ships back to England, while incorporating the provision ships and the largest Spanish warship into his own fleet.

After Rodney’s fleet passed Cape St. Vincent on the southwestern tip of the Iberian Peninsula, they encountered the Spanish squadron sent to intercept them—nine ships of the line and two frigates, under the command of Admiral Don Juan de Langara.

Langara drew his ships into a line of battle and prepared for action. But as the British sails came nearer, he realized he had made a fatal mistake. Instead of a facing a few British warships escorting a large convoy of merchant vessels, as he had assumed, he saw that what was actually bearing down on him was a powerful fleet of 18 ships of the line and 7 frigates. Outgunned over two to one, Langara ordered his ships to break and run for the port of Cadiz.

The impressive British victory that followed—the first major British naval victory of the war—was made possible by two things: a technological advantage and lucky weather. 

When the Spanish ships turned and ran for the coast, Rodney ordered “General Chase,” meaning his ships could break line and pursue the enemy individually at full speed. The Spanish ships were of superior design and construction and with their head start should have been able to escape. But the British vessels were far faster and were able to run the Spanish down due to a technological advance—copper sheathing on the ships’ bottoms which prevented barnacles and other marine life from growing on them. With sundown fast approaching, the copper-sheathed British ships began to overtake the slowest of the Spanish warships. Rodney issued orders to attack “in rotation,” meaning that as a British warship caught a Spanish ship, it was to fire a broadside into it, then continue the chase, with each succeeding British ship to do the same. (By the way, Rodney was suffering from an attack of gout and spent the entire battle confined to his bunk, relaying his orders through orderlies.)

The Spanish ship that had the misfortune to be bringing up the rear was the 74-gun Santo Domingo. She had already taken three broadsides from British ships racing past her when the HMS Bienfaisant caught her and fired into her at about 4:40 p.m. With that blast the Santo Domingo exploded, killing every man aboard, save one.

At this point weather intervened to allow the British victory to be complete. Normally, in the 18th century it was not possible to fight naval battles at night. But this night was clear, and under a bright full moon the British fleet continued to chase, overtake, and capture the Spanish ships. The last two of the Spanish warships to be taken were pounded into submission at about 1 a.m. Only three of the Spanish ships escaped. The British had suffered 141 casualties, the Spanish had over 5,000, along with the lost ships. 

The next day Rodney and his fleet sailed into Gibraltar, resupplying the beleaguered garrison there, with both the provisions they had brought from Great Britain and those they had captured from the Spanish. 

The Battle of Cape St. Vincent, also remembered as “the Moonlight Battle,” occurred on January 16, 1780, two hundred forty-five years ago today.

The painting is “The Moonlight Battle off Cape St. Vincent, 16 January 1780,” by Richard Paton, depicting the explosion of the Santo Domingo, with Rodney’s flagship HMS Sandwich in the foreground.