Pereiaslav Agreement in the context of "Alexis of Russia"

The Union of Russia and Ukraine Tercentenary or the Reunification of Ukraine with Russia Tercentenary (Russian: 300-летие воссоединения Украины с Россией, 300-letiye vossoyedineniya Ukrainy s Rossiyei; Ukrainian: 300-річчя возз'єднання України з Росією) was a republic-wide celebration within the Soviet republics of Russia and Ukraine, starting in February 1954, in celebration of the union between Russia and Ukraine formed by the 1654 Pereiaslav Agreement.

In preparation for the event, a special Republican commission for commemoration of the union between Russia and Ukraine Tercentenary was formed, headed by the First Secretary of the Communist Party of Ukraine Alexei Kirichenko. A three-volume body of documents and materials titled as "Reunification of Ukraine with Russia" was published in 1953 in Moscow, prepared jointly by the History Institute of the Academy of Sciences of the Soviet Union, History Institute of the Academy of Sciences of the Ukrainian SSR, and the Ukrainian Directorate of Archives, and included 747 documents of the period between 1620 and 1654. The materials were prepared by a group of Soviet Russian and Ukrainian historians organized in 1952 and approved by the Central Committee of the Communist Party of the Soviet Union.

The Cossack Hetmanate (Ukrainian: Гетьма́нщина, romanized: Hetmanshchyna; see other names), officially the Zaporozhian Host (Ruthenian: Войско Zапорожскоε; Ukrainian: Військо Запорозьке, romanized: Viisko Zaporozke; Latin: Exercitus Zaporoviensis), was a stratocratic Zaporozhian Cossack state established by Registered Cossacks in Dnieper Ukraine. Its territory was located mostly in region of Central Ukraine, as well as in parts of Belarus and southwestern Russia, and at different points it also incorporated the territories of Zaporozhian Sich to the south. The Hetmanate existed between 1649 and 1764, although its administrative-judicial system persisted until 1781. In different periods it was a vassal of the Polish–Lithuanian Commonwealth, Ottoman Empire and Russian Empire.

The Hetmanate was founded in the eastern territories of the Polish–Lithuanian Commonwealth by the Treaty of Zboriv, signed on August 18, 1649 by Bohdan Khmelnytsky (Hetman of the Zaporizhian Host) and Adam Kysil (representing Crown Forces), as a result of Khmelnytsky Uprising. Establishment of vassal relations with the Tsardom of Russia in the Treaty of Pereiaslav of 1654 is considered a benchmark of the Cossack Hetmanate in Soviet, Ukrainian, and Russian historiography. The second Pereiaslav Council in 1659 restricted the independence of the Hetmanate, and from the Russian side there were attempts to declare agreements reached with Yurii Khmelnytsky in 1659 as nothing more than the "former Bohdan's agreements" of 1654. The 1667 Treaty of Andrusovo, conducted without any representation from the Cossack Hetmanate, established the borders between the Polish and Russian states, dividing the Hetmanate in half along the Dnieper and putting the Zaporozhian Sich under a formal joint Russian-Polish administration.

The Khmelnytsky Uprising, also known as the Cossack–Polish War, Khmelnytsky insurrection, or the National Liberation War, and Cossack Revolution, was a successful Cossack rebellion with elements of religious war that took place between 1648 and 1657 in the eastern territories of the Polish–Lithuanian Commonwealth, resulting in Cossack victory and the creation of the Cossack Hetmanate in present-day Ukraine. Under the command of Cossack Hetman Bohdan Khmelnytsky, the Zaporozhian Cossacks, allied with the local Ruthenian (Ukrainian) peasantry and initially the Crimean Tatars, fought against the Commonwealth's forces. The war was accompanied by mass atrocities committed by Cossacks against prisoners of war and the civilian population, especially Poles, Jews, Roman Catholic and Ruthenian Uniate clergy, as well as savage reprisals by the Polish szlachta and the loyalist Jeremi Wiśniowiecki, the voivode of Ruthenian descent (military governor) of the Ruthenian Voivodeship.

The uprising has a symbolic meaning in the history of Ukraine's relationship with Poland and Russia. It ended the Polish Catholic szlachta's domination over the Ukrainian Orthodox population; at the same time, it led to the eventual incorporation of eastern Ukraine into the Tsardom of Russia initiated by the 1654 Pereiaslav Agreement, whereby the Cossacks would swear allegiance to the tsar while retaining a wide degree of autonomy. The event triggered a period of political turbulence and infighting in the Hetmanate known as the Ruin. The success of the anti-Polish rebellion, along with internal conflicts in Poland and concurrent invasions waged by Russia and Sweden against the Poles, ended the Polish Golden Age and caused a secular decline of Polish power during the period known as "the Deluge".

The Cossack Hetmanate (Ukrainian: Гетьма́нщина, romanized: Hetmanshchyna; see other names), officially the Zaporozhian Host (Ruthenian: Войско Zапорожскоε; Ukrainian: Військо Запорозьке, romanized: Viisko Zaporozke; Latin: Exercitus Zaporoviensis), was a stratocratic Zaporozhian Cossack state established by Registered Cossacks in Dnieper Ukraine. Its territory was located mostly in the region of Central Ukraine, as well as in parts of Belarus and southwestern Russia, and at different points it also incorporated the territories of Zaporozhian Sich to the south. The Hetmanate existed between 1648 and 1764, although its administrative-judicial system persisted until 1781. In different periods it was a vassal of the Polish–Lithuanian Commonwealth, the Ottoman Empire and the Russian Empire.

The Hetmanate was founded in the eastern territories of the Polish–Lithuanian Commonwealth by the Treaty of Zboriv, signed on August 18, 1649 by Bohdan Khmelnytsky (Hetman of the Zaporizhian Host) and Adam Kysil (representing Crown Forces), as a result of the Khmelnytsky Uprising. Establishment of vassal relations with the Tsardom of Russia in the Treaty of Pereiaslav of 1654 is considered a benchmark of the Cossack Hetmanate in Soviet, Ukrainian, and Russian historiography. The second Pereiaslav Council in 1659 restricted the independence of the Hetmanate, and from the Russian side there were attempts to declare agreements reached with Yurii Khmelnytsky in 1659 as nothing more than the "former Bohdan's agreements" of 1654. The 1667 Treaty of Andrusovo, conducted without any representation from the Cossack Hetmanate, established the borders between the Polish and Russian states, dividing the Hetmanate in half along the Dnieper and putting the Zaporozhian Sich under a formal joint Russian-Polish administration.