St. Mikhail I, grand duke of Tver, Vladimir and Novgorod, was born in 1271, the second son of Jaroslav III Jaroslavitch, grand duke of Tver, Pleskau and Novgorod, and his second wife Xenija Jurievna. He succeeded his father as Prince of Tver in 1285. On 8 November 1294 he married Anna Dimitriejewna of Rostov, daughter of Dmitry Borisovitch, prince of Rostov. They had four sons and a daughter of whom Alexander and Konstantin are recorded as having progeny.
Upon the death of Andrei Alexandrovitsch (the eldest surviving son of Alexander Nevski, and Jaroslav's nephew), Mikhail became the grand prince of Vladimir in 1304, as was consistent with the Rota System of collateral succession that had been practised in Rus' since the time of Jaroslav I Vladimirovitch 'the Wise', grand duke of Kiev. He was confirmed in office by Tokhta, khan of the Golden Horde.
While he seemed secure in the throne, being the legitimate heir and having been confirmed by the khan in Sarai, Mikhail suffered a series of setback as grand prince which led him to losing the grand princely office for both himself and ultimately for his descendants. He was, like most grand princes of Vladimir, accepted as prince of Novgorod the Great in 1309, but he fought with Novgorod, going so far as to withdraw his lieutenants_(namestniki)_and cut off grain shipments into the city in 1312. While he was on decent terms with Tokhta Khan, and initially with his successor Uzbeg Khan (Mikhail paid homage on Uzbeg's accession to the throne in 1313 and remained in Sarai until 1315), he eventually lost influence to Yury, prince of Moscow, a grandson of Alexander Nevski, who gained influence in Novgorod while the grand prince was away in Sarai. Mikhail did manage to finally take control of the city in 1316 with Mongol aid, but the following year Uzbeg Khan gave the _yarlik_ or patent of office of the Grand Prince of Vladimir to Yury, who also married Uzbeg's sister. After granting Yury the patent of office, the Khan sent his army under the Mongol general Kavgadii to help Yury in his struggle with Mikhail. On 22 December 1317 Mikhail defeated Yury at the village of Bortenevo (40 km from Tver). Mikhail captured Yury's wife, who was the khan's sister. When she died in Mikhail's custody, he was blamed for her murder, although it seems unlikely that he would have killed her knowing how much it would hurt him politically for such little gain. He released Kavgadii, who returned to Sarai and accused Mikhail of murdering the khan's sister, withholding tribute, and warring against his Mongol overlord. As a result Mikhail was summoned to the Horde by the khan and executed on 22 November 1318.
Mikhail had also alienated the Church, particularly Metropolitan Petr. When Metropolitan Maksim died in 1305, Mikhail nominated another candidate, but Petr was consecrated by the Patriarch of Constantinople. Petr sided with Moscow and opposed Mikhail on several occasions. In 1309 he appointed David as archbishop of Novgorod, and David was instrumental in the argument that led Mikhail to withdraw his lieutenants and cut the grain supplies to the city. In 1314 Novgorod called on Yury to be named Grand Prince and for Mikhail to be deposed. Thus the support of the Church aided Yury to Mikhail's detriment. In spite of being out of favour with the Church in his lifetime, the Russian Orthodox Church later declared Mikhail a saint.
Mikhail's wife Anna took the veil in Kashin's nunnery and died there on 2 October 1368. She is commemorated as Anna of Kashin by the Russian Orthodox Church and was canonised in 1677.