Ivan Vyhovsky

Ivan Vyhovsky (Ruthenian: Іоан Виговский / Іоан Виговскій / Іоан(ъ) Выговскій / Иоан Виговс(ъ)кий; Ukrainian: Іван Виговський; Polish: Iwan Wyhowski / Jan Wyhowski; date of birth unknown, died 1664), served as hetman of the Zaporozhian Host (1657-1659), leading the Cossack Hetmanate during the Russo-Polish War (1654–1667). Vyhovsky belonged to an Orthodox noble family from Vyhiv near Ovruch in modern Zhytomyr Oblast. He succeeded the famous hetman and rebel leader Bohdan Khmelnytsky. His time as hetman was characterized by generally pro-Commonwealth policies and an attempt to establish a sovereign Grand Principality of Ruthenia within it by the Treaty of Hadiach (16 September 1658). However, when the Sejm of the Commonwealth unilaterally altered the terms of the treaty without his knowledge or consent in May 1659, an invasion by the Tsardom of Russia and revolts amongst the Zaporizhian Cossacks in the south eventually led to the end of his hetmanship in October 1659.