The Siege of Kyzykermen occurred in November 1655 when forces loyal to the deposed Khan of Crimea Mehmed IV Giray attacked the fortress of Kyzykermen (Beryslav), whose garrison remained loyal to Khan Islam III Giray.
With Azaq-kale (Azov) and the Don Steppe secure, Jerzy Wisniewski led Mehmed IV Giray's armies west to invade the Crimea itself. The rebels besieged Kyzykermen, which guarded the Dnipro River and could threaten the rebel army's rear as it advanced into the Crimea. When Wisniewski approached the garrison commander Alpdogan Bayramoglu and asked for his surrender, Bayramoglu agreed as long as Wisniewski gave him a bribe of 20,000 thaler. However, Wisniewski refused to pay such a hefty bribe, and he instead decided to storm the city. The rebels rushed through the gates and attacked the garrison of dismounted bajrak and jasaq light cavalry, kapikulu regulars, seymen marksmen, and veteran Janissaries. In the ensuing slaughter, the garrison fought to the last man, inflicting significant casualties on the besiegers. However, the rebels ultimately conquered Kyzykermen, giving them a base from which to either invade Crimea or secure the Kilburun Fortress on the Black Sea.