abstract:Qasim Khanate or Kingdom of Qasim (Tatar: Qasím xanlığı/Касыйм ханлыгы, Qasím patşalığı/Касыйм патшалыгы; , Касимовское царство) was a Tatar khanate, vassal of Russia, which existed from 1452 till 1681 in the territory of modern Ryazan Oblast in Russia with its capital Kasimov, in the middle stream of the Oka River. Its khans were the patrilineal descendants of Toqa Temür, the thirteenth son of Jochi and grandson of Genghis Khan.