The following year, in 1621, an army of 100,000–160,000 Turkish soldiers led by Sultan Osman II in person advanced from Adrianople towards the Polish frontier, but the disaster of Cecora caused the Commonwealth to mobilise a large army (of about 25,000 Poles and 20,000 Cossacks) in response. Hetman Chodkiewicz crossed the Dniester in September 1621 and entrenched himself in the fortress of Khotyn on the very path of Ottoman advance. It was here that, for a whole month (2 September to 9 October), during the Battle of Khotyn, the Commonwealth hetman held the sultan at bay, up until the first autumn snow. The deaths of his men compelled Osman to withdraw. However, the victory was to be dearly ransomed by Poland. A few days before the siege was raised, the aged grand hetman died of exhaustion in the fortress on September 24, 1621. After his death the Polish forces were led by Stanisław Lubomirski.