Boris of Tver

Boris of Tver or Boris the Great (ca. 1399–February 10, 1461) was a prince of Tver.
Boris, the son of Alexander II of Tver, was Grand Prince of Tver from April 22, 1426 to his death. He first married to Anastasia Andreevna of Mozhaysk and had a daughter Maria of Tver (future wife of Ivan III of Moscow), second to Anastasia Alexandrovna of Suzdal, and had two sons - Mikhail III of Tver and Alexander.
During his reign, the story of Third Rome ("the second Constantine") started in Tver, when the monk Foma (Thomas) of Tver had written The Eulogy of the Pious Grand Prince Boris Alexandrovich in 1453.