On 16 May 1648, Bohdan Khmelnytsky's forces overwhelmed and defeated Commonwealth’s forces under the command of Stefan Potocki at the Battle of Zhovti Vody. Stefan's father, Grand Crown HetmanMikołaj Potocki, was unable to send reinforcements in time to relieve him; however, with the number of defections from the force that was sent to fight Khmelnytsky (over 5,000 registered Cossacks switched their allegiance), it is doubtful that the reinforcements could have helped defeat the combined Cossack and Tatar army of 18,000. From his fortified position beyond Chyhyryn, fifteen miles from Zhovti Vody, Mikołaj Potocki signaled a retreat on 13 May to the north. Near Cherkasy, the lone survivor from the battle at Zhovti Vody reached Potocki on 19 May with news of the disastrous defeat. Two days later, in 21 May, Potocki had only made it as far as the present-day city of Korsun-Shevchenkivskyi when he decided to wait for Jeremi Wiśniowiecki's army of 6,000 Poles.
The retreat started at dawn, during which the Cossack and Tatar armies allowed Potocki's forces to pass until they reached Horokhova Dibrova, about a mile and a half from Korsun, at noon. This proved to be disastrous, as Bohdan Khmelnytsky had ordered his First Polkovnyk (Colonel) Maksym Kryvonis (aka "Crooked-nose" or Perebyinis) to prepare a trap in this "swampy valley between two precipices", including trenches and a barricaded road. The resulting chaos as the Commonwealth's forces entered an impenetrable valley allowed Khmelnytsky's forces to flank them from both sides, quickly slaughtering whole divisions. Only about 1,500 of the Commonwealth’s forces (under a Colonel Korycki) managed to escape. Both Hetmans were taken prisoner, and the rest of the army was either captured or killed.
^(in Ukrainian)Terletskyi, Omelian: "History of the Ukrainian Nation, Volume II: The Cossack Cause", page 76. 1924.
^Hrushevsky, M., 2002, History of Ukraine-Rus, Volume Eight, The Cossack Age, 1626-1650, Edmonton: Canadian Institute of Ukrainian Studies Press, ISBN1895571324