In 1285 he built a stone church in honor of the Savior’s Transfiguration in place of the wooden church of Saints Cosmas and Damian. Upon the death of Great Prince Andrew Alexandrovich (+1305), Michael went to the Horde and received the grant to the great princely throne by right of seniority. But Prince Yurii Danilovich of Moscow would not submit to this, because he sought the princely rule for himself. He was often at the Golden Horde of the new Khan Uzbek, who had accepted Mohammedanism and was distinguished by his cruelty and fanaticism. Prince Yurii knew how to please the Khan, and he married his sister Konchaka and became Great Prince.
Even then he did not calm down, but instead began an internecine war with Tver. In Yurii’s army was a detachment of Tatars sent by Uzbek, with Kavgadi at the head. But the men of Tver, with holy Prince Michael at the head, on December 22, 1317 defeated Yurii. Many captives were taken, including Kavgadi, whom Saint Michael released, and the Moscow prince’s wife Konchaka, who unexpectedly died at Tver.
Prince Yurii slandered Saint Michael before the Khan, accusing him of poisoning Konchaka. The Khan became enraged, threatening to destroy Saint Michael’s princely holding, and demanded that he appear to give an account. Not wishing to spill Russian blood in an unequal struggle with the Khan, Saint Michael humbly went to the Horde, knowing that this meant death for him. He bid his his family and the Tver people farewell, and received a blessing for his exploit of martyrdom from his spiritual Father Igumen John.
“Father,” said the saint, “I was much concerned for the peace of Christians, but through my sins, I was not able to stop internecine war. Now give me your blessing, so that if my blood is spilled for them, they might have some respite, and that the Lord will forgive my sins.”
At the Horde an unjust trial was held, which found the saint guilty of disobedience to the Khan, and sentenced him to death. They removed him under guard and put him in a heavy wooden stock. As was his habit, Saint Michael constantly read the Psalter in prison and blessed the Lord for granting him to suffer for Him. He asked not to be abandoned in his present torments. Since the hands of the holy sufferer were secured in the stock, a boy sat before him and turned the pages of the Psalter. The holy captive languished at the Horde for a long time, enduring beatings and ridicule. They suggested that he flee, but the saint bravely answered, “In all my life I never fled from an enemy. If I save myself and my people remain in peril, what glory is that to me? No, let it be as the Lord wills.”
Through the mercy of God, he was not deprived of Christian solace: Orthodox priests attended to him, the igumens Alexander and Mark. Each week he made his Confession and received the Holy Mysteries of Christ, thus receiving a Christian preparation for his death. At the instigation of Prince Yurii and Kavgadi, who took revenge on the holy prince for their defeat, assassins rushed into the encampment where the captive was held. They fiercely beat the martyr and kicked him with their feet, then one of them stabbed Saint Michael with a knife.
The holy martyr’s naked body was exposed for abuse, and later they covered him with a cloth and placed him on a large board attached to a cart. By night two guards were set to watch the body, but fear seized them and they fled. In the morning, his body was not on the board.
On the previous night many, not only Orthodox but also Tatars, had seen two radiant clouds shining over the place where the body of the martyr lay. Although many wild animals roamed the steppes, not one of them had touched him. In the morning everyone said, “Prince Michael is a saint, and was innocently murdered.” From the Horde the body of the prince was transferred to Moscow, where they buried him in the church of the Savior-Wood in the Kremlin.
Just a year later, in 1318, the people of Tver learned the fate of their prince. At the wish of his wife, the right-believing Princess Anna of Kashin (October 2), and at the request of the people of Tver, the relics of Saint Michael were transferred to his native city, and on September 6, 1320 were placed in the church he built in honor of the Transfiguration of the Lord. Local veneration of the holy Prince began soon after the transfer of his relics to Tver, and the general Church glorification of the saint took place at a 1549 Council.
On November 24, 1632 the incorrupt relics of Saint Michael were uncovered. The holy Prince has often helped the Russian land. In 1606 the Polish and Lithuanians besieging Tver repeatedly saw a wondrous horseman ride out from the city upon a white horse with sword in hand , turning them to flight. Later, when they saw an icon of holy Prince Michael, they affirmed with an oath to Archbishop Theoctistus of Tver that the horseman was indeed Saint Michael himself.