out on August 15, 1327 after Chol-khan's men attempted to confiscate a mare from a local deacon named Dudko; the people gathered to protect Dudko, and subsequently spread out and began to assault Mongol forces throughout the city. Chol-khan attempted to entrench himself against the mob inside the palace, but when the building was lit on fire, he perished. Tartars throughout Tver were slaughtered, including the "Bessermen," Tartar merchants. Some chronicles and modern historians believe that Alexander instigated the uprising, but this is unlikely considering the consequences that such a violent rebellion would have. However, he did not take any measures to suppress the insurrection. The prince of Moscow, Ivan Kalita, a long time rival of the princes of Tver, hastened to take advantage of the uprising in order to assert his supremacy. Ivan allied with the Golden Horde and volunteered to help restore the power of the Mongols over Tver. In return, Öz Beg promised to make Ivan the Grand Duke and reinforced his army with 50,000 Mongol warriors under the command of five Mongol generals. The prince of Suzdal also joined the Russo-Mongol punitive expedition that came to be known as the "Army of Fedorchuk," named after the Tatar commander Fedorchuk. In retaliation, the Russo-Mongol army took dozens of captives and burned entire villages to the ground. Alexander fled to Novgorod, who turned him away, and then to Pskov, where he was made the prince, to escape capture by Ivan. Novgorod managed to avoid the wrath of the army for involving themselves with the prince by paying the Mongol horde two thousand silver hryvnias and providing them with many gifts. Meanwhile, Ivan and his allies demanded the extradition of Alexander from Pskov, and Metropolitan Theognostus of Kiev excommunicated the prince and all the people of Pskov from the church. In order to alleviate the threat of invasion from his host city, Alexander fled once again to Lithuania in 1329, where he would remain for over a year. Aftermath The uprising greatly reduced the Tver Principality's power in the northeastern remains of Kievan Rus'. In 1328, Öz Beg granted Ivan Kalita the duchies of Novgorod and Kostroma. Alexander Vasilyevich, the prince of Suzdal, received Vladimir and a region encompassing present day Nizhny Novgorod and Gorodets. By granting the more prestigious Vladimir to the weaker of the two princes, Öz Beg maintained adherence to the principle of "divide and rule,"