After Bohdan Khmelnytsky died in 1657, Ukraine become more instable, leading to conflicts between pro-Polish and pro-Muscovite factions of Cossacks. In 1658, hetman Ivan Vyhovsky negotiated the Union of Hadiach, which would set up a three-part Commonwealth, incorporating the Cossack Hetmanate as the "Grand Duchy of Ruthenia" on equal footing with the current members: the Kingdom of Poland and the Grand Duchy of Lithuania. However, the fall of Vyhovsky meant that this wouldn't come to fruition, as conflicts continued within the Cossack state. By 1660, the state was essentially divided along the Dnieper river, with a Polish-controlled west and a Muscovite-controlled east. In 1663, Cossacks rebelled against the Commonwealth and with the help of the Crimean Tatars in 1665, Hetman Petro Doroshenko took power, with the hopes of taking Ukraine out from under both Muscovy and the Polish–Lithuanian Commonwealth. The two powers had completely ignored the Hetmanate's interests and partitioned the Hetmanate along the Dnieper in the Truce of Andrusovo. In 1666, Doroshenko restarted Cossack correspondence with the Ottomans.