Mikhail, the holy Grand Duke of Tver, son of Yaroslav III, grandson of Yaroslav II Vsevolodovich, was born in 1272, shortly after his father's death, from his second wife Xenia; he was nicknamed Tversky, because he reigned in Tver before he was grand duke, and the first to establish the independence of the Tver principality. After the death of Grand Duke Andrei Alexandrovich of Tver (1304), Mikhail was supposed to ascend the grand ducal throne, but his nephew, George 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 Mikhail, who defeated his army and captured George and Konchaka, but mercifully granted them freedom. Unfortunately, Konchaka died suddenly, and Georgy and the Tatar commander Kavgady slandered Mikhail in front of the Uzbek. On the banks of the Nerl River, Mikhail parted from his mother and confessed his sins to his confessor, while he himself headed for the horde, going almost to certain death. He understood that in this way he was laying down 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, bringing charges based on the testimony of slanderers. Without 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 received the Holy Mysteries several times, 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. The faithful 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 troubled within me, and the fear of death attacks me." His soul involuntarily shuddered. When he closed the book, one of the boys 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 men, and he stood alone and prayed. The villains threw him to the ground, tortured him, and beat him with their heels. One of them, named Romanets, stabbed him in the ribs and cut out his heart (November 22, 1318). 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.
Mikhail's wife, Anna, begged George to allow the prince's remains to be transported to Tver. Tverites met the coffin of their beloved prince on the banks of the Volga River. After removing the lid of the coffin, the people saw with inexpressible joy the integrity of the relics, which had not been damaged by a long journey. The burial was performed on September 6, 1320 in the Transfiguration Monastery. The holy relics of the blessed prince were found incorruptible in 1655.
The chronicler calls Michael the same Fatherland lover as St. Demetrius of Thessalonica. In addition to the virtues of the state, Mikhail was distinguished by his family qualities, brought up in the rules of piety by his virtuous mother Xenia, who died her days as a nun.