The Ruin was a period of civil warfare within the Ukrainian Cossack Hetmanate that lasted from 1657 to 1686, resulting in the partition of Ukraine between Poland-Lithuania, Russia, and the Ottomans. Left-bank Ukraine with Kyiv and Zaporizhia would come under Russian control, while right-bank Ukraine came first under Polish control and then under partial Ottoman control.
Following the death of the Cossack liberator Bohdan Khmelnytsky in 1657, a succession crisis broke out, with his son Yurii Khmelnytsky fighting to take his father's place. However, the young and inexperienced Yurii lacked the charisma and leadership qualities of his father. At the same time, the Poles wanted to take the Ukrainian lands back, the Tsardom of Russia sought to replace Cossack liberty with Muscovite autocracy, the Crimean Khanate carried out regular slave raids against its Slavic neighbors, and the Ottoman Turks showed little concern for the Ukrainian frontier. The Orthodox church favored closer ties with Moscow, while richer and poorer Cossacks were politically divided.
Ivan Vyhovsky became regent for the young Yurii on Bohdan's death in 1657, basing his power on the starshina Cossack elite and seeking a rapprochement with Poland. More democratic Cossacks like Martyn Pushkar and Yakiv Barabash responded by rebelling against Vyhovsky, and the ensuing civil war cost about 50,000 lives before the rebels were defeated in June 1658. In September 1658, Vyhovsky signed a treaty with Poland that would transform Ukraine into a member of the Polish-Lithuanian Commonwealth, but the treaty was never implemented due to the renewal of the Russo-Polish War. The Russians were defeated at the Battle of Konotop in June 1659, but Vyhovsky was forced to step down by several pro-Moscow colonels in October 1659 and retired to Poland. Yurii Khmelnytsky assumed the hetmanate, but, a year later, he signed a treaty with Russia limiting the hetmanate's autonomy and transforming Ukraine into a Russian vassal. The Poles won several victories against the Russians and forced Yurii to return Ukraine to the commonwealth, causing Yakym Somko and the Cossacks of left-bank Ukraine to depose him. In January 1663, Yurii - depressed by his partition of Ukraine - retired to a monastery.
In the left bank, Ivan Briukhovetsky ruled as a Russian puppet, allowing Russian tax collectors and soldiers into his realm. Right-bank leader Pavlo Teteria pursued a pro-Polish policy and, although he failed to conquer the left bank, he helped suppress numerous revolts against the Poles before being forced into exile by his anti-Polish opponents. At the same time, Petro Doroshenko created a 20,000-man band of mercenaries to fight against the starshina elite, allying with the Turks. In 1667, the Ottomans and Cossacks invaded Galicia and forced the king to grant extensive autonomy to Doroshenko. In 1668, Doroshenko removed the rival hetman from power on the left bank and declared himself hetman of a united Ukraine; Briukhovetsky was beaten to death by a mob angered at Russia's growing power. However, Crimea backed a rival hetman and the Poles backed Mykhailo Khanenko. Demian Mnohorishny, Doroshenko's governor of the left bank, allowed the Russians to assume control of that region. In 1672, Doroshenko helped the Turks annex Podolia, but his assistance to non-Christians cost him popularity and forced him to cede power to Ivan Samoylovych in 1676. Samoylovych agreed to limited powers, becoming a puppet of the starshina and the Russians. In 1687, he contributed 50,000 Cossacks to Russia's failed invasion of the Crimea, and he was blamed for the allied defeat and was exiled to Siberia. Meanwhile, in 1678, the Turks appointed Yurii Khmelnytsky as the Cossacks' new hetman, but they deposed him in 1681. By then, the Right Bank had been severely depopulated by warfare, Tatar slaves raids, and population movements to the Left Bank or Sloboda Ukraine (the country's northeast frontier with Russia).
In 1687, Ivan Mazepa was elected as hetman, merging left-bank Ukraine with the Hetmanate as part of Russia. Russian demands for Cossack aid during the Great Northern War ultimately led to Mazepa's rebellion against Peter the Great in 1708, but his revolt was crushed at the Battle of Poltava and Mazepa forced to flee to Turkey. The Ruin ended Khmelnytsky's attempt to create a Ruthenian Cossack state, Ukraine was partitioned between Russia and Poland along the Dnieper, Poland's loss of the left bank caused its decline, Russia expanded to the south and rose in power, and Turkey briefly expanded its power into Ukraine until 1699.