From the 14th to the 17th century the Ottoman Turks were a serious force to contend with in Europe. In fact, in 1453 the Turks finally captured Constantinople, the last vestige of the Roman Empire. They continued their sweep into south-central Europe, threatening to overrun Vienna and thus conquer the rest of Christendom!
However, on October 7, 1571 the Turks were soundly defeated at the naval battle of Lepanto in the eastern Mediterranean. It was not easy to put together a European coalition to fight the Turks, but finally Spain, some German/Austrian forces and several smaller Italian states came together (“The Holy League”) against the common threat. The Spaniards supplied the money and the core of elite fighting men. And the Venetians (the only naval power capable of dealing as an equal to the Turks) supplied most of the ships.
This was the last major engagement between galley ships (being powered by teams of rowers along with sails). The two navies combined had over 400 ships! The Turks had more ships and fighting men, but miraculously the Holy League utterly destroyed the Turkish navy in fierce hand-to-hand combat. Some 15,000 Christian slaves were liberated from Islamic captivity, and the Turkish navy never again seriously threatened Christian Europe.
Although the Turks continued to push into Europe with land forces, they were finally destroyed at the Battle of Vienna some 100 years later.
Many thanks to the Italians (especially the Republic of Venice), the Spaniards and the Germans from rescuing Europe from tyranny long, long ago.
Imagine if the battle had gone the other way.