It is difficult to establish exactly when Islam first appeared in Russia because the lands that Islam penetrated early in its expansion were not part of Russia at the time, but were later incorporated into the expanding Russian Empire. Islam reached the Caucasus region in the middle of the seventh century as part of the Arab conquest of the Iranian Sassanid Empire, many centuries before Russian expansion into this region, 1 and the archeological evidence points to the existence of links between the people of Bashkortostan, located in contemporary Russia's Ural Mountains region, and the Islamic world dating back to the eighth century.2 By the tenth century, the Bulghar Kingdom on the banks of the Volga River had accepted Islam and incorporated Bashkortostan into its domain, almost half a millennium before Russia's conquest of the region under Tsar Ivan IV (Ivan the Terrible). Before the arrival of the Russians, the Bulghar Kingdom developed into an important center of Islamic civilization, with extensive ties to the rest of the Islamic world, especially Central Asia and Khorasan.3 This fact prompted the nineteenth-century Russian philosopher and historian S.M. Soloviev to state, "When the Bulghar was already listening to the Qu'ran on the shores of the Volga and the Kama, the Russian Slav had not yet started to build Christian churches on the Oka and had not yet conquered these places in the name of the European civilization."4