Volga Tatar history
Tatars inhabiting the Republic of Tatarstan, a federal subject of Russia, constitute one third of all Tatars, while the other two thirds reside outside Tatarstan. The formation of some of the communities residing outside Tatarstan took place before the Russian Revolution of 1917 due to Tatars being specialized in trading.
The emergence of ethnonym "Tatar" is disputed, with two theses trying to explain its origins. The Mongol thesis, according to which etymology can be traced back to the Chinese "Ta-Tan" or "Da-Dan", is more widely accepted than Turkic one. Ethnonym "Tatar" first emerged in the fifth century CE/AD.
The 14th century saw the spread of Sunni Islam among the Tatars. Tatars became subjects of Russia after the Siege of Kazan in 1552. Since Russians linked Tatars with the Mongol Golden Horde (that ruled Russia in the 13th century), they began to negatively stereotype the Tatar people. Due to these negative stereotypes, some of which persist in modern Russian society, recently some Tatar intellectuals have been trying to link Tatar heritage with the historic Bulgar population of today's Tatarstan. Russians were using the Tatar ethnonym during the 18th and 19th centuries to denote all Turkic inhabitants of the Russian Empire, however the Turkic peoples of the Russian Empire before the emergence of the Soviet Union did not usually self-identify as Tatars. Up to the end of the 19th century, Volga Tatars mainly identified themselves as Muslims until the rehabilitation of the ethnonym Tatar occurred. Russian officials used literary Tatar language to interact with the Turkic peoples of the Russian Empire before the end of the 19th century. Volga Tatar role in the Muslim national and cultural movements of the Russian Empire before the 1917 Revolution is significant and this situation continued even after 1917. Tatar authorities attempted in the 1990s to reverse the Russification of Tatarstan that took place during the Soviet period.