Holy League (1717)
The Holy League of 1717 was one of many coalitions organised by the Papal States to deal with the Ottoman threat. This last one comprised Portugal, the Republic of Venice and Malta.
Background
Throughout the 16th and 17th centuries several Holy Leagues were organized by the Papacy, 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 18th century, and came again to the fore in the Seventh Ottoman–Venetian War of 1714–1718.
As with the previous Leagues, the Papal States organized the expedition, the Republic of 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.
Aftermath
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.
After the Battle of Matapan however, the Ottoman Empire could no longer keep up with the technological race and eventually the European fleets came to dominate the whole of the Mediterranean.