Islam in Tatarstan existed prior to the tenth century, but it began major growth in 922, when Bulgar ruler Almış converted to Islam. This was followed by an increase in missionary activity in Volga Bulgaria. Islam remained the dominant religion through the Mongol invasion and subsequent Khanate of Kazan. In 1552, the region was finally conquered by Russia, bringing the Tatars and Bashkirs on the Middle Volga into the tsardom. Under Russian rule, Islam was suppressed for many years, first during the Tsardom and Empire and later during the Soviet era. Today, Islam is a major faith in Tatarstan, adhered to by to 53 percent of the estimated 3.8 million population, making it the largest religion.