The Battle of Korsun was the second major battle of the Khmelnytsky Uprising, occurring on 26 May 1648 in present-day Ukraine. Following the disastrous 16 May Battle of Zhovti Vody, the Polish Great Hetman Mikolaj Potocki halted his advance into Ukraine at Korsun and decided to await the arrival of Prince Jeremi Wisniowiecki's army of 6,000 troops. Field Crown Hetman Marcin Kalinowski and Great Crown Hetman Potocki and their 5,000-strong army took a stand and awaited Bohdan Khmelnytsky's advance parties, who crossed the Tiasmyn River and then the Ros River into Korsun. Potocki ordered Korsun burned and placed his army in front of the camp, where he skirmished with the Tatars before retreating down the road to Bohuslav. The Cossacks and Tatars, led by Maksym Kryvonis, ambushed the Poles in a swampy valley, and only around 1,000 of the Polish forces were able to escape, while the rest were captured or killed. Both hetmans were among the captured, leaving the Polish army without a commander.