Sources vary as to when the uprising ended. Russian and some Polish sources give the end-date of the uprising as 1654, pointing to the Treaty of Pereyaslav as ending the war; Ukrainian sources give the date as Khmelnytsky's death in 1657; and few Polish sources give the date as 1655 and the Battle of Jezierna or Jeziorna (November 1655). There is some overlap between the last phase of the Uprising and the beginning of the Russo-Polish War (1654–1667), as Cossack and Russian forces became allied.