In 1719 the castle was garrisoned by 46 Spanish soldiers who were supporting the Jacobites. They had established a magazine of gunpowder, and were awaiting the delivery of weapons and cannon from Spain. The English Government caught wind of the intended uprising and sent three heavily armed frigates The Flamborough, The Worcester, and The Enterprise to quell matters. The bombardment of the castle lasted three days, though met with limited success due to the enormity of the castle walls, which in some places are up to 14 feet thick. Finally, Captain Herdman of The Enterprise sent his men ashore and over-whelmed the Spanish defenders. Following the surrender, the government troops discovered the magazine of 343 barrels of gunpowder which was then used to blow up what had remained from the bombardment…!