The campaign of 1445 was disastrous for Muscovy and had major repercussions in Russian politics. Hostilities broke out when Khan Ulugh Muhammad took the strategic fortress of Nizhny Novgorod and invaded Muscovy. Vasily II mustered an army and defeated the Tatars near Murom and Gorokhovets. Thinking the war over, he disbanded his forces and returned to Moscow in triumph, only to learn that the Tatars had besieged Nizhny Novgorod again.

A new army was mustered and marched towards Suzdal, where they met the Russian generals who had surrendered Nizhny to the enemy after setting the fortress on fire. On 6 June 1445 the Russians and the Tatars clashed in the Battle of the Kamenka River near the walls of St. Euphemius Monastery. The battle was a resounding success for the Tatars, who took Vasily II prisoner. It took four months and an enormous ransom (200,000 roubles) to recover the monarch from captivity.