Throughout the XVII century several Holy Leagues were organised by Rome, the most famous of which finally managed to defeat the Ottoman fleet at the third Battle of Lepanto. However the resurgent threat of the Ottoman fleet continued until the early XVIII century.
As with the previous Leagues, Rome organised the expedition, Venice financed it and a third party - usually a catholic kingdom - was to provide the backbone of the fleet. Given that Spain was exhausted from the War of the Spanish Succession, the Pope appealed to Portugal which ended up sending a fleet to the Mediterranean.
The efforts came to fruition in late July, when a combined fleet of Portuguese, Venetian, Papal and Maltese ships defeated the fleet of Kapudan Pasha Ibrahim Pasha in the Battle of Matapan.
The outcome of 1717 as well as of the prior battles with the same goal, was that of restricting the Ottoman naval dominance to the eastern Mediterranean.