San Sebastian was a key part of Vigo’s town defences, due to its location at one end of the town walls and its proximity to Castro Castle. However, it was also dependant on being protected by Castro Castle. If the castle fell then San Sebastian would be easy to capture, followed then by the town itself.

In 1665, when the Portuguese invaded the land near to Vigo, the fortification of San Sebastian had still not been completed. However, the Portuguese stopped at the town gates and did not attempt to attack the town.

During the English invasion in 1719, Castro Castle was the focus for the Spanish defence of the town. The local people followed orders and evacuated the town. The Spanish troops, after blowing up one of its bastions, abandoned San Sebastian. This was captured by the English and from there they fired upon Castro Castle. Without any supplies and after suffering a number of casualties, the Spanish troops surrendered the castle after six days, of, what the English described as, a barbaric defence. It would take a number of years to repair the damage caused by this attack on Vigo.

In 1809 the town was occupied by the French, and, when they were defeated, they left behind 17 empty carts and a number of starving horses and mules.

Impact of the attack in 1719, according to a British army major and possible spy

"This is a large fishing town. Fish are in great abundance, an so extremely cheap, that I could buy a hundred of sardiñas, which are as a large as sprats for a quart*. The devastation committed by the English in the year 1719, is still recent; and the inhabitants have not yet recovered their losses. I was ashamed to hear of the licentious acts of my countrymen, sill mentioned with horror, who pillaged the people, and wantonly plundered an set fire to their houses: such seats of cruelty are unworthy of their character: indeed such a method of carrying on a war is paltry; to destroy the property and take away the little serapings of a few individuals tend not either to the glory of the nation, or conduce towards drawing matters to a conclusion; it is only becoming the dissolute manner of pirates and buccaneers."

Letter XII of “Travels through Spain and Portugal”, William Dalrymple (1774)