.
Polish-Lithuanian Background: By about 1362 (
Battle of Blue Waters), most of northwest Ukraine (including Kiev) had fallen to Lithuania. In 1385 (
Union of Krewo), the crowns of Poland and Lithuania were joined into the
Polish–Lithuanian union and Lithuania became Christian, the last European country to do so. In 1569 (
Union of Lublin), during the Livonian War, a
closer union was made and most of Ukraine was transferred from Lithuania to Poland. In 1596 (
Union of Brest), an attempt was made at church union. The Orthodox would retain their rites and married clergy while accepting the doctrinal supremacy of the Pope. Since some Orthodox rejected this, the effect was to create three churches instead of two. From about 1610, the Orthodox and
Zaporozhian Cossacks became more closely allied, thereby increasing the alienation of both from Poland. From about 1637, there were rebellions in the eastern lands which led to a movement of population into Russian territory south of the Belgorod Line (
Sloboda Ukraine).
Khmelnytsky: In 1648,
Bohdan Khmelnytsky started a rebellion which quickly became a general Orthodox rising against Poland, extending as far west as Volhynia. It also became something of a social revolution as landowners, Poles, Catholics, and Jews were driven west. Khmelnytsky sought Russian support, but Russia hesitated, knowing that this would lead to a major war with Poland. In 1654, Russia accepted Khmelnitsky as a vassal (
Treaty of Pereyaslav).
Russo-Polish War (1654–1667): Anticipating that the Treaty of Pereyaslavl would mean war with Poland, Russia struck first, taking Smolensk. In 1665, Sweden attacked Poland leading to the near-collapse of the Commonwealth (
the so-called 'Deluge'). Instead of finishing off Poland, Russia and Sweden fell out (
Russo-Swedish War (1656–1658), giving the Commonwealth time to recover. By the
Treaty of Andrusovo in 1667, Russia acquired Smolensk and Chernihiv and nominal rule over the lands east of the Dnieper, including Kiev. To the south of this, Zaporizhia was in theory a Russo-Polish condominium, but in practice continued under Cossack self-government. By the
Eternal Peace Treaty of 1686, Poland gave up its claim to Zaporizhia.
The Ruin: After Khmelnytsky's death in 1657, it proved impossible to maintain a Cossack state. The area was effectively divided at the Dnieper from 1660. The partition of Andrusovo was done without Cossack consent. See
The Ruin (Ukrainian history). During this period, Doroshenko allied with the Turks, bringing Ottoman armies onto the steppe for the second, and final time (
Russo-Turkish War (1676–1681). (dark green) and of the territory of the
Zaporozhian Cossacks (purple) under the rule of the Russian Empire (1751)
Ukraine Partitioned: After 1667, eastern Ukraine was divided into four areas. The
Right Bank of the Dnieper gradually returned to Polish control. On the
Left Bank was the
Cossack Hetmanate under Russian suzerainty. Over the next hundred years, it was slowly converted into a group of normal Russian provinces. To the east of this and south of the Belgorod Line was the
Sloboda Ukraine. This area, newly settled by immigrants from further west, retained a Cossack way of life, but Russia never permitted a Cossack political organization. South of the Hetmanate on the Dnieper bend, Zaporizhia was nominally subject to the Hetmanate but was practically self-governing. Over the next century, these areas shared the fate of the Hetmanate.
The Izium Line: From 1680, a triangular area south of the Belgorod Line in the
Sloboda Ukraine was fortified. The new line was 530km long and enclosed 30,000 square km. It pushed the frontier another 160km southward to within 150km of the Black Sea coast. From Userdsk west of the southeast corner of the Belgorod Line, it ran southwest to
Valuyki (1593,625s,60s) and then south down the
Oskol River to its juncture with the Donets (750s) below the old site of Tsarev-Borisov which was apparently reestablished. It then turned northwest up the Donets past
Izium,
Zmiiv, and
Valky to Kolomak (650s,150w) with an extension southwest down the Kolomak River to
Poltava. Kolomak is about 60km southwest of the west end of the Belgorod Line at Okhtyrka. The area inside the line corresponds approximately to
Kharkiv Oblast and contains the modern city of
Kharkiv which began as a small fort about 1630. ==1686–1783: To the Black Sea==