KASIMOV, a town of Russia, in the government of Ryazañ, on the Oka river, in 54° 56′ N. and 41° 3′ E., 75 m. E.N.E. of Ryazañ. Pop. (1897), 13,545, of whom about 1000 were Tatars. It is famed for its tanneries and leather goods, sheepskins and post-horse bells. Founded in 1152, it was formerly known as Meshcherski Gorodets. In the 15th century it became the capital of a Tatar khanate, subject to Moscow, and so remained until 1667. The town possesses a cathedral, and a mosque supposed to have been built by Kasim, founder of the Tatar principality. Near the mosque stands a mausoleum built by Shah-Ali in 1555. Lying on the direct road from Astrakhan to Moscow and Nizhniy-Novgorod, Kasimov is a place of some trade, and has a large annual fair in July. The waiters in the best hotels of St Petersburg are mostly Kasimov Tatars.
See Veliaminov-Zernov, The Kasimov Tsars (St Petersburg, 1863–1866).