„Булгар ал-Џадид“

  In the XIIIth century the Bulgar state was one of the first who held out in the wars with the Mongol troops. In 1236 the Bulgar state fell under the pressure of the Mongol-Tatars. Many towns, i.e. Bulgar, Bilyar, Suvar, etc. were destroyed and set on fire. In the XIII-XIVth CC. the territory of the Volga-Kama Bulgaria became the part of the Turkic state Zolotaya Orda (Golden Hord). The collapse of Zolotaya Orda resulted in formation of a number of new states including the Kazan Khanate. It inherited ethnic, language, religious, cultural and trade-economic traditions of the Volga-Kama Bulgaria. Kazan became the capital of the newly formatted state. The Kazan Khanate ceased its existence in October 1552, after two-month siege when troops of Ivan 4 (the Terrible), numbering 150,000 people, conquered Kazan.

The Bulgar thesis traces the ancestors of the Kazan Tatars to the Bulgars – a Turkic people who penetrated the Middle Volga and lower Kama region during the first half of the eighth century after being displaced from the Azov steppes by frequent Arab campaigns.At the heart of this thesis is the idea that, when the lands of the Bulgars were conquered by the Mongol Tatars in 1236 and 1237, their culture survived the demise of the political entity and provided a foundation for the emergence of the Kazan Tatars.