1719
After the discovery of the Cellamare Conspiracy, the Duc d'Orléans ordered a French army under the Duke of Berwick to invade the Basque provinces of Spain in April 1719. This army met very little resistance, but was forced back by heavy losses due to disease. A second attack in Catalonia suffered the same fate. In the Americas, the French were more successful and took Pensacola in Florida.
In Sicily, the Austrians started a new offensive under Count Claude Florimond de Mercy. They first suffered a defeat in the Battle of Francavilla (20 June 1719). But the Spanish were cut off from their homeland by the British fleet and it was just a matter of time before their resistance would crumble. Mercy was then victorious in the second Battle of Milazzo, took Messina in October and besieged Palermo.
It was also in 1719 that the Irish exile, the Duke of Ormonde, organized an expedition with extensive Spanish support to invade Britain and replace King George I with James Stuart, the Jacobite "Old Pretender." However, his fleet was dispersed by a storm near Galicia in 1719, and never reached Britain. A small force of 300 Spanish marines under George Keith, tenth Earl Marischal did land near Eilean Donan, but they and the highlanders who supported them were defeated in the Battle of Glen Shiel in June 1719, and the hopes of an uprising soon fizzled out.
In retaliation for this attack, a British fleet captured Vigo and marched inland to Pontevedra in October 1719. This caused some shock to the Spanish authorities as they realized how vulnerable they were to Allied amphibious attacks, with the potential to open up a new front away from the French frontier.
The French captured the Spanish settlement of Pensacola in Florida in May 1719, pre-empting a Spanish attack on South Carolina. While Spanish forces retook the town in August 1719, it fell to the French again towards the end of the year who destroyed the town before withdrawing.
A 1,200 strong Spanish force set out from Cuba to take the British settlement of Nassau in the Bahamas. After taking a large amount of plunder they were eventually driven off by the local militia.
Read more about this topic: War Of The Quadruple Alliance