Tver (tvĕr) [key], formerly Kalinin kəlyēˈnyĭn, city (1989 pop. 451,000), capital of Tver region, central European Russia, at the confluence of the Volga and Tver rivers. A major port on the upper Volga, it is linked with Moscow by the Moscow Canal. An industrial center, Tver has industries producing linen textiles, light machinery, and rolling stock. The city grew around a fort established in the late 12th cent. It was early an important trade center, and from the mid-13th cent. until the late 14th cent. it was the seat of a powerful principality that rivaled Moscow. It was subjugated (1475–85) by Ivan III, grand duke of Moscow. Tver was renamed (1931) for M. I. Kalinin, a president of the USSR. It reverted to its original name in 1992. It is the site of a cathedral and castle, both from the 17th cent.