Is it true that Ukraine was “reunited” with Russia in 1654?

The “reunification" of Ukraine with Russia was the official term for the 1654 Pereiaslav Treaty; the term was prescribed for oblig­atory use in Soviet historical works and public discourse by the Communist Party's Central Committee in 1954.

What really happened in 1654, however? In 1648 the disaffected Cossack officer Bohdan Khmelnytsky launched a rebellion against Polish rule, which, unlike earlier such uprisings, developed into a full-scale war with armies fighting each other in the field. The con­flict had features of a peasant war, with villagers rising en masse against the economic order, but it was also a religious war of the Orthodox against the Catholics and Jews. A contemporary Jewish chronicler described the Cossack slaughter as an “abyss of de­spair," and indeed, scholars estimate that the rebels killed as many as 18,000 to 20,000 of the 40,000 Jews in the land.³ The same fate awaited Catholic Poles and Uniate Ukrainians, who did not manage to escape before the advancing Cossack army.

By the early 1650s, however, military setbacks forced Khmelnytsky to search for allies other than the unreliable Tatars. Orthodox Muscovy appeared to be a natural choice, not only because of shared religion, but also because it was Poland's long-standing rival in the region. Yet Tsar Alexei was hesitant to lend support to the Cossacks precisely because this would mean another exhaustive war with Poland. Only the very real danger of Khmelnytsky accepting the suzerainty of the Ottoman Empire prompted the Russians to act. After protracted negotiations, Russian envoys arrived in January 1654 to the Ukrainian town of Pereiaslav (just south of Kyiv) to fi­nalize the agreement. The final text of the treaty has been lost, and historians have been arguing for centuries whether the signatories had in mind a temporary political and military alliance or an irre­versible voluntary incorporation. One thing is certain: the signing ceremony itself revealed deep-seated differences between the two countries' political models. After the Cossack officers took an oath of allegiance to the tsar, they expected the Muscovite envoys to re­ciprocate with an oath in the tsar's name to observe the rights of the Cossacks. Yet the Russians refused, because for them the tsar was an absolute monarch not accountable to his subjects.

Following the signing of this treaty, the Cossack lands that cor­respond approximately to present-day central Ukraine became a protectorate of the Russian tsars, who from then on referred to them­selves as rulers of Great and Little Russia (i.e., Russia proper and Ukraine). The Cossack polity preserved full autonomy in internal affairs and the right to conduct foreign policy independently, except in interactions with Poland and the Ottomans, which theoretically required Moscow's approval, but in practice the Cossack leaders ignored this provision. Following a protracted war with Poland and Khmelnytsky's death in 1657, however, the Muscovite government began increasingly limiting the Hetmanate's sovereignty, which caused discontent among the Ukrainian Cossacks.