Kashin princes in 60-80s of the XIV century

In the following paper the author researches the significance of Kashin as an important centre of the Tver Principality during the reign of Grand prince Vasily Mikhailovich and the confrontation between Moscow and Tver, Kashin unstable position of the princes, caused by the struggle of parties among the local ruling elite, caught between the two centers of power. As a result, the part of the elite continued to focus on Tver, while the other gave preference to Moscow. The latter position prevailed, which led to the refusal of the Prince of Kashin from the treaty with Mikhail and his involvement in the campaign against Tver in 1375. Special attention is paid to the growth of local separatism, the fate of the Kashin Principality under the treaty of 1375, securing its secession from the supreme power of Tver, as well as the short period of its formal independence and the circumstances of its return to Tver in 1382. The influence of the Kashin princes’ kinship ties, especially the marriage of Kashin prince Mikhail Vasilievich and the Moscow princess Vasilisa Semenovna, is also analyzed, the reasons, circumstances and significance of this marriage in the light of Moscow-Tver relations in the 60-80s of the XIV century in the general context of conjugal unions of the two leading principalities of North-Eastern Rus.