The Poles followed this advice; the Tsar accepted their offer. When the service required had been rendered the treaty was broken. In the same year, however, Vygovski was deposed by the Cossacks, the treaty of Gadyach rejected, and Yuri Hmelnitski made hetman. The Cossacks were again in agreement with Moscow; but the Poles spared no effort to bring Yuri to their side, and they succeeded through the deposed hetman, Vygovski, who adhered to the Commonwealth so far.
Both sides were preparing their heaviest blows at this juncture, and 1660 brought victory to the Poles. In the beginning of that year Moscow had some success in Lithuania, but was forced back at last toward Smolensk. The best Polish armies, trained in the Swedish struggle, and leaders like Charnyetski, Sapyeha, and Kmita, turned the scale in White Russia. In the Ukraine the Poles, under Lyubomirski and Pototski, were strengthened by Tartars and met the forces of Moscow under Sheremetyeff, with the Cossacks under Yuri Hmelnitski. At the critical moment, and during action, Yuri deserted to the Poles, and secured the defeat of Sheremetyeff, who surrendered at Chudnovo and was sent a Tartar captive to the Crimea.
In all the shifting scenes of the conflict begun by the resolute Bogdan, there was nothing more striking than the conduct and person of Yuri Hmelnitski, who renounced all the work of his father. Great, it is said, was the wonder of the Poles when they saw him enter their camp. Bogdan Hmelnitski, a man of iron will and striking presence, had filled the whole Commonwealth with terror; his son gave way at the very first test put upon him, and in person was, as the Poles said, a dark, puny stripling, more like a timid novice in a monastery than a Cossack. In the words of the captive voevoda, Sheremetyeff, he was better fitted to be a gooseherd than a hetman.
The Polish generals thought now that the conflict was over, and that the garrisons of Moscow would evacuate the Ukraine; but they did not. At this juncture the Polish troops, unpaid for a long time, refused service, revolted, formed what they called a “sacred league,” and lived on the country. The Polish army vanished from the field, and after it the Tartars. Young Hmelnitski turned again to Moscow, and writing to the Tsar, declared that, forced by Cossack colonels, he had joined the Polish king, but wished to return to his former allegiance. Whatever his wishes may have been, he did not escape the Commonwealth; stronger men than he, and among them Vygovski, kept him well in hand. The Ukraine was split into two camps: that west of the river, or at least the Cossacks under Yuri Hmelnitski, obeyed the Commonwealth; the Eastern bank adhered to Moscow.
Two years later, Yuri, the helpless hetman, left his office and took refuge in a cloister. He was succeeded by Teterya, a partisan of Poland, which now made every promise to the leading Cossacks, not as in the old time when the single argument was sabres.
East of the Dnieper another hetman ruled; but there the Poles could take no part in struggles for the office. The rivalry was limited to partisans of Moscow. Besides the two groups of Cossacks on the Dnieper, there remained the Zaporojians. Teterya strove to win these to the Commonwealth, and Yan Kazimir, the king, assembled all the forces he could rally and crossed the Dnieper toward the end of 1663. At first he had success in some degree, but in the following year led back a shattered, hungry army.
Teterya had received a promise from the Zaporojians that they would follow the example of the Eastern Ukraine. The king having failed in his expedition, Teterya declared that peace must be concluded between the Commonwealth and Moscow to save the Ukraine; that the country was reduced to ruin by all parties, neither one of which could subjugate the other; and that to save themselves the Cossacks would be forced to seek protection of the Sultan.
Doroshenko succeeded Teterya in the hetman’s office, and began to carry out this Cossack project. In 1666 he sent a message to the Porte declaring that the Ukraine was at the will of the Sultan.
The Sultan commanded the Khan to march to the Ukraine. Toward the end of that year the Tartars brought aid to the Cossacks, and the joint army swept the field of Polish forces.
Meanwhile negotiations had been pending a long time between the Commonwealth and Moscow. An insurrection under Lyubomirski brought the Poles to terms touching boundaries in the north. In the south Moscow demanded, besides the line of the Dnieper, Kieff and a certain district around it on the west. This the Poles refused stubbornly till Doroshenko’s union with Turkey induced them to yield Kieff to Moscow for two years. On this basis a peace of twenty years was concluded in 1667, at Andrussoff near Smolensk. This peace became permanent afterward, and Kieff remained with Moscow.