In 1610–12, at the height of the ‘Time of Troubles’, Poles had occupied Moscow, their mercenaries massacring inhabitants and their domineering Catholicism alienating the nobility. Accordingly, when the Zaporozhian Cossacks rose in revolt against Poland in land seized from Russia, Tsar Alexis saw the opportunity for revenge. The revolt began in 1648 and, under the leadership of Bohdan Khmelnytsky, Kiev was quickly taken. Ultimately, the rebels ranged as far west as Lvov, and declared an independent Cossack state. Their rule was marked by pogroms of both Catholics and of Jews. In the 1650s, the Polish/Lithuanian Commonwealth fought back, and Khmelnytsky reluctantly accepted Russian vassalage in return for their military support, by the Treaty of Pereyaslavl (1654). Through the war that followed (complicated by the intervention of Sweden), Russia reclaimed Smolensk, eastern Ukraine and Zaporozhia from Poland by the Treaty of Andrusovo (1667).
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