After destroying the Byzantine Empire in 1453, the Ottoman Empire turned its attention toward Europe, aiming to take advantage of upheaval caused by various European conflicts.
The Turks employed two strategies: using their navy to attack the Mediterranean and invading central and eastern Europe with their land armies.
Despite some brief successes, their attempt to gain naval supremacy would effectively be ended by a crushing defeat at the battle of Lepanto in 1573. But by the middle of the 16th century, they controlled Serbia, Albania, Croatia, Bosnia and even parts of Hungary.
However, an attempt to extend their territory deeper into Europe ultimately met with failure. The Ottoman forces launched an attack on the rest of Hungary and Austria in 1682, and by the summer of 1683 they had besieged Vienna. In response, troops from Poland and the Holy Roman Empire attempted to relieve the city.
A day after the coalition arrived outside the city gates, the two forces clashed. In the resulting battle, which involved one of the largest cavalry charges in history, the Ottomans were routed, despite having greater numbers.
The battle proved to be a turning point. By 1699, the Ottomans not only had to abandon their designs on Austria, but also had to relinquish their Hungarian possessions. They would continue to make occasional attempts to expand westwards during the 18th century and their empire would not be wound up until 1922.
But most historians date its decline from that day outside the gates of Vienna. Certainly, it would never again pose a serious threat to Europe.