1640s in the Polish–Lithuanian Commonwealth

The Khmelnytsky Uprising, also known as the Cossack–Polish War, or the Khmelnytsky insurrection, was a Cossack rebellion that took place between 1648 and 1657 in the eastern territories of the Polish–Lithuanian Commonwealth, which led to the creation of a Cossack Hetmanate in Ukraine. Under the command of hetman Bohdan Khmelnytsky, the Zaporozhian Cossacks, allied with the Crimean Tatars and local Ukrainian peasantry, fought against Commonwealth's forces. The insurgency was accompanied by mass atrocities committed by Cossacks against prisoners of war and the civilian population, especially Poles, Jews and Roman Catholic and Ruthenian Uniate clergy, as well as savage reprisals by loyalist Jeremi Wiśniowiecki, the voivode of Ruthenian descent (military governor) of the Ruthenian Voivodeship.