Khmelnytsky's campaign of 1648

In January 1648, Khmelnytsky with his son Tymofiy Khmelnytsky headed to the Zaporozhian Sich with several hundred Cossacks that joined them. They took out the Polish garrison that guarded the Sich, allowing them to take control of it and get access its military power. Khmelnytsky mobilised numerous Cossacks and peasant militias for his campaign. He also concluded an alliance with the Crimean Khanate.^[8]

The Polish forces became aware of an unrest that was occurring in the Left-Bank Ukraine and Khmelntsky's insurgent army. Mikołaj Potocki was sent out with his army to put down the uprising.^[9] In April, the army sent out to Ukraine was made up of 30,000 troops.^[3]

The Battle of Zhovti Vody was the first major confrontation of the uprising. Many of the registered Cossacks defected to the rebels during the battle. The Polish forces were surrounded and made a desperate attempt to break out at night, but were caught in an ambush and completely defeated on 5–6 May.^[10] Up to 3,000 Polish troops were captured out of 5,000 with the rest killed and a few manahing to escape. The Cossack-Tatar losses didn't exceed 150 killed and the same amount of wounded.^[11]

In May, another battle took place known as the Battle of Korsuń. The Polish army was made up of 20,000 troops while the Cossack-Tatar army had 15,000-20,000 troops. However, the Polish army feared to meet the fate of defeat at Zhovti Vody and attempted to retreat from their positions. They were harassed by Cossack forces and forced parts of the army to trying passing through the muddy forest.^[11] Their artillery and carts were stuck in the mud, which the Cossack army under Maksym Kryvonis used as an opportunity to strike the clashing blow on the Polish forces, As a result of the battle, 8,500 Polish soldiers were captured with the rest killed. Only 1,500 troops managed to flee.^[12]

The series of defeats suffered by the Polish noble army in Left-Bank Ukraine made many of them reconsider the idea of attempting to suppress the uprising there. Jeremi Wiśniowiecki with several thousands troops attempted to mobilise the Polish forces in Left-Bank for the struggle, but he himself was ultimately forced to retreat to the Right-Bank Ukraine with the rest of the nobles. Wiśniowiecki intended to employ scorched earth policy here in attempt to slow down the rebel forces.^[12]

After the Cossack victories on the Left-Bank, Khmelnytsky captured Bila Tserkva and intended to move on the Right-Bank Ukraine. His hopes of resolving the conflict diplomatically have shattered after the death of King Władysław IV Vasa, left only with the magnets that sought to protect their endangered property. Jeremi Wiśniowiecki and other Polish nobles entered Podolia during summer.^[13] The devastation was accompanied by mutual cycle of violence which targeted Polish, Ruthenian and Jewish civilians. Jews were targeted by Cossacks as they were believed to have been representatives of the Polish nobility.^[2]

In July, Wiśniowiecki's forces suffered defeats against Cossack leader Maksym Kryvonis during the Battles of Makhnivka and Kostiantyniv. Fighting also took place Lypovets (present-day Vinnytsia Oblast) and other settlements, which forced the Polish forces to entrench themselves in fortresses and open fighting. However, one such fortress that was considered to be impregnable was captured by colonel Kryvonis which had proven to be a massive moral blow.^[13] The bloody fighting was accompanied by mutual atrocities on the civilian population.^[3]

At the end of summer, Polish government sent out a 40,000-strong army with the purpose to suppress the uprising, which included 8,000 German mercenaries.^[3] Both sides in total could've had up to 100,000 troops at this stage. A major battle was going to take place at Pyliavtsi. The turning point of the battle occurred when a captured Cossack gave a misleading information to the Polish forces, stating that the Crimean Khan with a huge army was coming to the aid of Cossacks. In reality, only a small unit of Budjak Tatars arrived, but nonetheless the presented misleading information put the Polish army into the state of panic and subsequent disorganised retreat on 14 September. Many of the Polish troops were taken prisoner and their equipment was captured. After this victory, Cossacks mockingly nicknamed the Polish nobles who participated in this battle "pylyavtsy".^[2] Cossacks captured Volhynia and Podolia after their triumph at Pyliavtsi.^[1]

In October, the Kodak fortress capitulated to Cossacks.^[8] The Cossack-Tatar army besieged Lviv. Kryvonis's detachments captured the high castle over the city. However, Khmelnytsky made a decision to simply collect tribute as he didn't want to risk the devastation of the city by his Tatar allies in case Lviv was fully captured. Cossack army also entered Belarus and surrounded Jeremi Wiśniowiecki's forces at Zamość during this stage. Khmelnytsky again limited himself to collecting tribute and his campaign was completed by the time John II Casimir Vasa was elected as new King in November, with his coronation supported by Khmelnytsky.^[1][3]

The 1648 campaign ended in a major victory for the Zaporozhian Cossacks and led to their gains up to the western Galicia.^[1] Nonetheless, Khmelnytsky still believed in reaching compromise and recognition of his de facto newly established state as part of the triune Commonwealth, which was to include the Crown of the Kingdom of Poland, Grand Duchy of Lithuania and Hetmanate of Ukraine.^[14]

On 2 January 1649, Bohdan Khmelnytsky entered Kyiv.^[3] He was greeted as the "Moses, the savior, deliverer and liberator of the Rus' people from the slavery of the Lyaks [Poles]... the most enlightened ruler of princely Rus'".^[1] Bohdan Khmelnytsky was nicknamed "The Whip of God" (also called "The Scourge of God") by the Poles. This nickname was previously given to Attila of the Huns who were known for bringing terror to the Western and Eastern Roman Empires, also known to have ruled over the territory of present-day Ukraine.^[6] The Khmelnytsky Uprising of 1648 became known as one of the largest and most successful revolts of the 17th century, which led to formation of the Cossack Hetmanate and allowed it to become a major player in European affairs during the 1650s.^[15]

• Палій, Олександр (2017). Історія України [A History of Ukraine] (in Ukrainian). Vol. 3. Kyiv: К.І.С. ISBN 978-617-684-166-1.