| Conflict: | Battle of Zhvanets |
| Partof: | the Khmelnytsky Uprising |
| Date: | September — 16 December, 1653 |
| Place: | Zhvanets, Volhynian Voivodeship, Polish–Lithuanian Commonwealth |
| Result: | Cossack-Tatar victory |
| Combatant1: | Cossack Hetmanate Crimean Khanate |
| Combatant2: | Polish–Lithuanian Commonwealth |
| Commander1: | Bohdan Khmelnytsky İslâm III Giray |
| Commander2: | John II Casimir |
| Strength1: | 30,000–40,000 Zaporozhian Cossacks 20,000–35,000 Crimean Tatars |
| Strength2: | approximately 30,000 soldiers of the crown army, unknown number of Pospolite Ruszenie[1] 3,000 Transylvanian and Moldavian soldiers[2] |
| Casualties1: | Light |
| Casualties2: | no data available (many died of starvation and disease) |
The Battle of Zhvanets or the siege of Zhvanets (Ukrainian: Битва під Жванцем, Жванецька облога, Polish: Bitwa pod Żwańcem, Oblężenie Żwańca; September — 16 December, 1653) was fought between the Cossack Hetmanate and Crimean Khanate against the Polish–Lithuanian Commonwealth as a part of the Khmelnytsky Uprising. Near the site of the present-day village of Zhvanets in Ukraine, a forces of the Zaporozhian Cossacks and Crimean Tatars under the command of Hetman Bohdan Khmelnytsky and Khan İslâm III Giray defeated and successfully besieged the Polish–Lithuanian Commonwealth’s forces under the command of the Polish King John II Casimir. The siege ended with a unsatisfactory outcome and the Poles and Lithuanians agreed to renew the Treaty of Zboriv which was signed in 18 August 1649.
Despite poor quality of Polish soldiers and their officers, as cream of the Polish Army had been murdered in the Batih massacre (June 1652), the spring offensive of 1653 progressed successfully. The situation changed when Khmelnytsky’s Cossacks joined forces with Tatars commanded personally by Islam III Giray. When news of this reached King Jan Kazimierz Waza, he decided to abandon his positions in Bar, Ukraine, and head towards Zhvanets, to await Moldavian and Transilvanian reinforcements.
Polish forces camped at the confluence of the and the Dniestr rivers, building a pontoon bridge over the Dniester, to keep in touch with Bucovina. The reinforcements were inadequate: George II Rakoczi sent 2000 soldiers, while Gheorghe Stefan, only 1000.
Bohdan Khmelnytsky decided not to make a frontal attack of the Polish camp. Instead, he chose a long-lasting siege, which began in late August 1653, and dragged on throughout autumn into December. As time went by and the weather worsened, Polish defenders began to starve, and a number of soldiers fled their positions in search of food. The situation was anxiously observed by Khan Islam III Giray, who did not wish for complete destruction of Polish forces, as this would eventually strengthen the Cossacks, who, despite the temporary alliance, were his traditional enemies. Furthermore, in late autumn news from Moscow came: the Russians wanted to protect Ukraine, and wage war against Poland.
Under the circumstances, on December 16, 1653, Poles and Tatars agreed to an oral truce. Khmelnytsky had to end the siege: his only achievement was that the Poles agreed to renew the Treaty of Zboriv. Polish Army finally left the camp, while Cossacks headed towards Pereyaslav, where the Treaty of Pereyaslav was signed in 1654.