Russia continued its territorial growth through the 17th century, which was the age of Cossacks. In 1648, the peasants of Ukraine joined the Zaporozhian Cossacks in rebellion against Poland-Lithuania during the Khmelnytsky Uprising in reaction to the social and religious oppression they had been suffering under Polish rule. In 1654, the Ukrainian leader, Bohdan Khmelnytsky, offered to place Ukraine under the protection of the Russian Tsar, Aleksey I. Aleksey's acceptance of this offer led to another Russo-Polish War. Ultimately, Ukraine was split along the Dnieper River, leaving the western part, right-bank Ukraine, under Polish rule and the eastern part (Left-bank Ukraine and Kiev) under Russian rule. Later, in 1670–71, the Don Cossacks led by Stenka Razin initiated a major uprising in the Volga Region, but the Tsar's troops were successful in defeating the rebels.