Between 1354 (when the Ottomans crossed into Europe at Gallipoli) and 1526, the Empire had conquered the territory of present-day Greece, Bulgaria, Romania, Albania, Serbia, Macedonia, Montenegro, Bosnia, and Hungary. The Empire laid siege to Vienna in 1683. The intervention of the Polish King broke the siege, and from then afterwards the Ottomans battled the Habsburg Emperors until 1699, when the Treaty of Karlowitz forced them to surrender Hungary and portions of present-day Croatia, Slovenia, and Serbia. From 1699 to 1913, wars and insurrections pushed the Ottoman Empire further back until it reached the current European border of present-day Turkey.