 Polish commander Grand Lithuanian Hetman Jan Karol Chodkiewicz crossed the Dniester River in September 1621 with approximately 20,000 to 35,000 soldiers, joined by 10,000 more led by the future king of Poland, Prince Władysław Vasa.The Polish-Lithuanian army numbered 30,000 (18,000 cavalry, 12,000 infantry) and their allied Cossack army was composed of 25,000–40,000 troops—mostly infantry—led by ataman Petro Konashevych-Sahaidachny.The Cossacks had about 22 guns.