Battle of Vienna
The Battle of Vienna took place at Kahlenberg Mountain near Vienna on 12 September 1683 after the city had been besieged by the Ottoman Empire for two months. The battle was fought by the Holy Roman Empire 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. The defeat is often seen as a turning point for Ottoman expansion into Europe, after which they would gain no further ground. In the ensuing war that lasted until 1699, the Ottomans would cede most of Hungary to the Holy Roman Emperor Leopold I.
https://en.wikipedia.org/wiki/Battle_of_Vienna