The Battle of Konotop was fought between a Crimean Tatar-Cossack-Polish army led by Hetman Ivan Vyhovsky and a Russian-Cossack army led by Semyon Pozharsky and Semyon Lvov. The Russian army was defeated and the siege of Konotop lifted, but Vyhovsky was removed from power by pro-Russian Cossacks several months later.
After the death of the Cossack Hetmanate's ruler Bohdan Khmelnytsky, the Tsardom of Russia instigated power struggles among the Zaporizhian Cossacks in an effort to undermine their authority. Khmelnytsky's immediate successor Ivan Vyhovsky allied with the Poles against the treacherous Russians after Tsar Alexis of Russia signed a peace accord with Poland in 1656, effectively abandoning the 1654 Treaty of Pereyaslav. The Poles agreed to make central Ukraine an equal constituent nation of Poland-Lithuania as the Grand Principality of Rus. Ivna Bezpaly and his pro-Russian faction within the Sich allied with Russia, which sent Prince Grigory Romodanovsky to aid the Cossacks of left-bank Ukraine against the pro-Poles of right-bank Ukraine in the autumn of 1658. The Right-bank Cossacks under Hryhoriy Hulyanytsky captured Konotop for the pro-Polish Cossacks, resulting in Russia dispatching between 28,600 and 150,000 troops to assist Romodanovsky.
The new Russian army arrived at the Ukrainian border on 30 January 1659 and stood 40 days until negotiations between the rival Cossack factions fell through. The Russians defeated Vyhovsky at Romny and Lokhvytsia before Prince Aleksey Trubetskoy besieged Konotop and its 4,000-strong garrison. Hulyanytsky and his Cossacks refused to betray Vyhovsky and instead mounted a fierce and protracted defense of Konotop. They withstood incendiary shelling and an all-out assault on 21 April 1659, and, as the siege dragged on for 70 days, Vyhovsky secured the aid of the Crimean khan Mehmed IV Giray and his 30,000-strong army and a force of 4,000 Poles and Serbian, Moldavian, and German mercenaries.
On 24 July 1659, the two rival armies met southwest of Konotop. On 27 June, Vyhovsky attacked Trubetskoy's army and captured a number of the Russians' horses before driving them away and further into the steppe. The Cossacks were forced to retreat by a Russian counterattack, but Trubetskoy's pursuit separated his army from that besieging Konotop. On the morning of 29 June, Vyhovsky attacked Prince Semyon Pozharsky's army, feigning retreat before ambushing it. The Tatars advanced from the eastern flank and slaughtered almost every Russian soldier in Pozharsky's detachment, and they captured Pozharsky, Prince Semyon Lvov, both Princes Buturlin, Prince Lyapunov, Prince Skuratov, Prince Kurakin, and others. After the captive Pozharsky insulted the Khan by spitting in his face, the Tatars beheaded him and returned his head to the Russian camp. Trubetskoy ordered the lifting of the siege and withdrew from Ukraine, and the Cossacks attacked the retreating Russians, taking most of their artillery, military banners, and treasury.
The Russian defeat at Konotop prevented the Tsar from again mustering an army that strong, and he showed himself to the people in mourning clothes. He ordered people of all ranks to help fortify Moscow, and it was rumored that he planned to flee beyond the Volga. After the battle, the Tatar-Cossack alliance would collapse, and growing opposition to Vyhovsky's rule forced him to flee to Poland as both the rich Cossack elite and the Ukrainian peasantry ceased to support him. "The Ruin" would ensue within the Cossack Hetmanate, resulting in its absorption into Russia.