The Siege of Belgrade in 1688 was the fourth siege of that city, taking place during the Great Turkish War. Belgrade was at that time a part of the Ottoman Empire, and had been for 167 years. The Ottoman Empire was at war with the Holy League, the forces of which were led by the elector of Bavaria, Maximilian II Emanuel. The Austrians were also accompanied by many Serbian volunteers under the command of Jovan Monasterlija. Maximilian's forces lost 4,000 men in the assault, while the Turks lost 5,000. They would hold the city for two years, until the Turks returned to besiege it in 1690.