Mikhail, the holy Grand Duke of Tver, son of Yaroslav III, grandson of Yaroslav II Vsevolodovich, was born in 1272, soon after his father's death, from his second wife Xenia; nicknamed Tversky, because he reigned in Tver before he was still a grand duke, and the first confirmed the independence of the Tver principality. Upon the death of Grand Duke Andrei Alexandrovich of Tver (1304), Mikhail was supposed to ascend the grand ducal throne, but his nephew, Georgy Danilovich of Moscow, disputed this right with him. This litigation dragged on for many years, aggravated by George's intransigence and love of power and his family relations with the Tatars – he was married to Konchak, the sister of Khan Uzbek. Once again declaring himself the grand Duke, George opposed Michael, who defeated his army and captured George and Konchaka, but by his mercy granted them freedom. Unfortunately, Konchaka died suddenly, and George and the Tatar commander Kavgady slandered Mikhail in front of the Uzbek. On the banks of the Nerl River, Mikhail parted with his mother and confessed his sins to his confessor, and he himself went to the horde, going almost to certain death. He understood that in this way he puts his soul for his loved ones and for all his people.
In the beginning, the khan received Mikhail kindly, but after a while he ordered him to be tried, charging him on the basis of the evidence of slanderers. Not listening to the prince's excuses, he was taken into custody, ordered to be chained, and a heavy block was placed around his neck. Mikhail endured humiliation and torment with amazing firmness. Even on the way from Vladimir, he had several times partaken of the Holy Mysteries, as if preparing for death; now, seeing imminent death, he spent his nights in prayer and reading psalms. The prince's boy held a book in front of him and turned over the leaves, because Mikhail's hands were tied. Loyal servants offered the prince to leave secretly, but he replied: "Saving myself, I will not save the fatherland. God's will be done!" Just before the arrival of the villains, he opened the Psalter at random and read: "My heart is in turmoil within me, and the fear of death attacks me." His soul involuntarily shuddered. When he closed the book, one of the youths ran in to him and said that Prince George, Kavgady and a crowd of people were approaching the tent. They dispersed all of Mikhail's people, and he stood alone and prayed. The villains threw him to the ground, tortured him, beat him with their heels. One of them, named Romanets, plunged a knife into his ribs and cut out his heart (November 22, 1319). Mikhail's body lay naked while the crowd plundered the prince's property. 
George sent the body of the Grand Duke to Majary. There, many zealous people wanted to bring the body to the church, but the boyars did not allow this, putting it in a stable, and later avoided stopping at churches.
Finally, the body of the Prince-martyr was brought to Moscow and buried in the Kremlin's Spassky Monastery, in the Church of the Transfiguration. The blessed Princess Anna did not know about the martyrdom of her husband. A year later, Prince George returned from the khan with a grand ducal label. He brought with him from the Horde of Tver boyars and Prince Konstantin Mikhailovich. Then in Tver they learned about the death of St. Michael and about his burial in Moscow. Princess Anna and the children of the holy Prince asked the Prince of Moscow to transport the holy relics of the martyr to Tver. George barely gave his consent. Then the boyars were sent from Tver to Moscow to triumphantly transport the relics of St. Michael. Those who arrived in Moscow were vouchsafed to see the wondrous miracle by which the Lord was pleased to glorify His saint. Corruption did not touch his holy body at all. The messengers took the coffin with the relics of the saint and carried it with great honor to Tver. When the procession was approaching the city, Princess Anna with her sons Dimitri, Alexander and Vasily rode towards the Volga in nasady, and Bishop Varsonofy with the entire holy cathedral and countless people met the holy relics on the shore. The sobbing was great; There was no church singing behind the crying of the people. Princess Anna cried especially bitterly.
On September 6, 1320, the holy relics of the blessed Prince Mikhail were buried in the cathedral church of the Transfiguration of our Lord Jesus Christ, built by him, where his parents, Grand Duke Yaroslav Yaroslavich and Grand Duchess Xenia were buried.
It pleased the Lord to glorify His saint with many miracles. Even before the discovery of his honest relics, pious people prayed at his tomb for the resolution of their ailments and received healing. The local celebration of the blessed Prince Mikhail in Tver began, probably shortly after the transfer of his relics from Moscow; the All-Russian celebration was established for him at the Cathedral in 1549.
In 1606, Poles and Lithuanians attacked the Russian land; the enemies reached the Tver borders and severely devastated the country. But the Lord has sent a glorious defender to the Russian land. The enemies often saw a wonderful horseman riding out of the city on a white horse with a drawn sword in his hands. Fear then attacked the enemies, and they fled. When the leaders of the enemy army saw the icon of St. Michael, they swore to St. Theoktist of Tver (he ruled the Tver diocese from 1603 to 1609) that the wonderful horseman they saw was St. Michael.
The incorruptible relics of the martyr prince were found in 1632, on November 24. At the same time, many miracles happened at the tomb of the saint. Some saw a pillar of fire above the cathedral church, where the holy relics rested. In 1655, a disaster struck Tver – a severe pestilence began, and many people died from this disease. The then Archbishop of Tver, Lawrence (he ruled the Tver diocese from 1654 to 1657), with the blessing of the patriarch, transferred the relics of the saint to a new shrine. At the same time, the saint's tomb was carried around the city. And from the same day, the disease stopped. In memory of such a wonderful intercession of St. Michael, a procession was established in Tver.