The Treaty of Zboriv was signed on August 18, 1649, after the Battle of Zboriv when the Crown forces of about 25,000 led by king John II Casimir of Poland clashed against a combined force of Cossacks and Crimean Tatars, led by hetman Bohdan Khmelnytsky and khan İslâm III Giray of Crimea respectively, which numbered about 80,000.