However, the Treaty of Hadiach was never implemented. Following its signing, a massive Russian army (according to some sources up to 150,000 soldiers; about 100,000 of them were occupied by the siege of Konotop, the rest were massacred by Tatars when trying to follow after Vyhovsky's cossacks, resulting in 20 000-30 000 lost among the Russians) led by the Muscovy boyar Aleksei Trubetskoi crossed into Ukraine. In response, Vyhovsky led 60,000 Cossacks against the Russians alongside his Polish and 40,000 Tatar allies. Near Konotop, the Russians were soundly defeated. However, Vyhovsky was not able to capitalize on this victory, as the Russian garrisons in several Cossack towns continued to hold out and his Tatar allies were forced to return to the Crimea when it was attacked by independent Cossacks. Furthermore, pro-Russia unrest led by Ivan Bohun broke out again amongst the Cossacks. In 1659, faced with a second rebellion against his rule and unable to master the dangerous and chaotic forces vying for power in Ukraine, Vyhovsky surrendered the office of hetman and retired to Poland. In 1660, he was appointed Voivode of Kiev, a position he kept until his death in 1664. Kiev itself was held by the Russian troops in this period, after voivodes Vasily Sheremetev and Yuri Baryatinsky managed to repel two Vyhovsky's and one Polish assault on the city.