Treaty of Hadiach
After Khmelnytsky's death Ivan Vyhovsky was chosen as the Cossack Hetman. Vyhovsky represented the Cossack upper strata and sought independence from Russia through an alliance with Charles Gustav and then the Commonwealth, where some of the leaders understood and wanted to amend the erroneousness of the past policies. An appropriate treaty was prepared by Yuri Nemyrych, an Arian and the Chamberlain of Kiev, who represented Vyhovski, and on John Casimir's side Stanisław Kazimierz Bieniewski, Voivode of Chernihiv, among others. The Treaty of Hadiach was signed on September 16, 1658.