Гадячский договор
Teteria and along with Samiilo Bohdanovych-Zarudny were part of the Ukrainian delegation sent to Moscow in April to conduct the Treaty of Pereyaslav with the Tsardom of Russia, which placed the Cossack Hetmanate and the Zaporozhian Host under the protection of the Tsar. When Vyhovsky was proclaimed hetman, he was made the chancellor secretary to the hetman. He participated in the negotiations of the Treaty of Hadiach, which would restore Ukraine back into the Commonwealth, as a third and autonomous state, under the ultimate sovereignty of the King of Poland. The treaty led to a civil war known as The Ruin, when he openly supported pro-Polish policy and pressured the young, and inexperienced Yuri Khmelnytsky to abdicate.