Battle of Vienna

The Battle of Vienna took place at Kahlenberg Mountain near Vienna on 12 September 1683 after the imperial city had been besieged by the Ottoman Empire for two months. The battle was fought by the Holy Roman Empire led by the Habsburg Monarchy and the Polish–Lithuanian Commonwealth, both under the command of King John III Sobieski, against the Ottomans and their vassal and tributary states. The battle marked the first time the Commonwealth and the Holy Roman Empire had cooperated militarily against the Ottomans, and it is often seen as a turning point in history, after which "the Ottoman Turks ceased to be a menace to the Christian world".

Source: Wikipedia