Sviatoslav declares his intention of establishing a Russo-Bulgarian empire with its capital at Pereyaslavets (now Perejaslav-Chmel'nickij) on the Danube River.

Transferring his capital here in 969, …

…Pereyaslav.

Yaroslav, to back up an armistice signed with Constantinople in 1046, had married his fourth and favorite son by Ingigerd Olafsdottir, Vsevolod, to the Greek Anastasia (d. 1067), who tradition holds was a daughter of Emperor Constantine IX Monomachos by his second wife (he gained the Imperial throne through his third marriage), but no reliable source has ever been found to confirm this.

However, the couple's son Vladimir Monomakh bears the family name of that emperor, giving the story credence.

Upon his father's death in 1054, Vsevolod receives in appanage the towns of Pereyaslav, …

Pereiaslav-Khmelnytskyi, which is to play a significant role in the history of Ukraine, is mentioned for the first time in the text of the Rus' treaty with Constantinople (911) as Pereyaslav-Ruskyi, to distinguish it from Pereyaslavets in Bulgaria.

Vladimir I, Prince of Kiev, had built a large fortress here in 992 to protect the southern limits of Kievan Rus' from raids of nomads from steppes of present southern Ukraine.

The Cumans, as Constantinople calls the non-Moslem, northern Oghuz Turks, had first encountered the Rus' in 1055, which had resulted in a peace agreement.

In 1061, however, the Cumans invade and devastate the Pereiaslav principality, supposedly breaching the earthworks and palisades that had been constructed by Princes Vladimir (d. 1015) and Yaroslav (d. 1054).

The Cumans defeat the armies of the three sons of Yaroslav the Wise—Iziaslav Yaroslavych, Sviatoslav II Yaroslavych, and Vsevolod Yaroslavych—in 1068 at the Alta River.

After the Cuman victory, they will repeatedly invade Ukraine, devastating the land and taking captives, who had become either enslaved to the Cumans or are sold at markets in the south.

The most vulnerable regions are the principalities of Pereiasla, …

Yaropolk has to deal with the many interests of his family, most of all his powerful half brother Yuri Dolgoruki.

Yaropolk had appointed Vsevolod Mstislavich to succeed him in Pereyaslav but Yuri Dolgoruki, with the consent of the Novgorodians, had soon driven out his nephew.

Yaropolk had appointed another son of Mstislav I: Iziaslav Mstislavich to Pereyaslav, who also received Turov.

He is replaced soon thereafter by Yaropolk's brother Viacheslav Vladimirovich.

The peace doesn't last.

Iziaslav has to transfer Turov to his uncle Viacheslav in 1134 to let him rule the principality once again.

Pereyaslav will come to Yuri Dolgoruki on the condition that Iziaslav is allowed to rule Rostov although Yuri keeps a large part of the principality under his influence.

Iziaslav also receives the rule over Volyn; another half brother of Yaropolk, Andrey Vladimirovich, is to rule Pereyaslav.

Sviatoslav continues the war against Yaropolk with Yaropolk's old enemies, the Cumans, on his side.

He soon meets before the gates of Chernigov the combined troops of Kiev, Pereyaslav, Rostov, Polotsk, Smolensk, parts of Halych and thirty thousand Hungarians, sent by the Hungarian king Bela II.

He is forced to make peace in 1139.

Yaropolk, just before his death, assists Bela II in facing internal enemies; dying in 1139, Yaropolk is buried in the church of St. Andrey.

His brother, Vyacheslav I, succeeds him but is soon driven out by Vsevolod II.

The Russian principality fractures into eight parts, following the example set by Poland in the previous year.

...Pereiaslav, and ...

Khmelnytsky declares in February 1649, during negotiations with a Polish delegation headed by senator Adam Kysil in Pereiaslav, that he is "the sole autocrat of Rus" and that he has "enough power in Ukraine, Podolia, and Volhynia... in his land and principality stretching as far as Lviv, Chełm, and Halych".

It becomes clear to the Polish envoys that Khmelnytsky has positioned himself no longer as simply a leader of the Zaporozhian Cossacks, but that of an independent state and states his claims to the heritage of the Rus'.

The Khmelnytsky Uprising is the precursor to a period in Polish history known as The Deluge (which includes a Swedish invasion of the Commonwealth), that is to temporarily free the Ukrainians from Polish domination but in short time subject them to Russian domination.

Weakened by wars and stalemated by the Poles, in 1654 Khmelnytsky persuades the Zaporozhye Cossacks to obtain military aid from Russia in exchange for their recognition of the tsar’s sovereignty over the Ukraine.

The rebellion against Polish rule ends in 1654 with the Zaporozhye Cossacks now firmly in the Russian camp by the Treaty of Pereyaslav, which will soon lead to the Russo-Polish War of 1654-1667.