In the siege of Belgrade (15 September – 8 October 1789) a Habsburg Austrian army led by Feldmarschall Ernst Gideon von Laudon besieged an Ottoman Turkish force under Osman Pasha in the fortress of Belgrade. After a three-week leaguer, the Austrians forced the surrender of the fortress. During the campaign which was part of the Austro-Turkish War, the Austrian army was greatly hampered by illness. Austria held the city until 1791 when it handed Belgrade back to the Ottomans according to the terms of the peace treaty. Several Austrian soldiers who distinguished themselves during the siege later held important commands in the subsequent French Revolutionary Wars and Napoleonic Wars. Belgrade is the capital of modern Serbia.