Actually, initially the Tatars are far from being one people. These are several separate ethnolinguistic groups that are quite close in their language. The latter was obtained during the Golden Horde era, but, with the exception of that time, they had their own ethnic and political history.
Although, of course, the Volga-Ural Tatars have a closer origin, to the point that the Kazantsev, Mishars, Teptyars, Kryashens and Nagaibaks can be considered subethnoses of a single nation. But those who live outside their traditional area did not enter this nation until very recently.
Siberian Tatars, very conditionally, are descendants of ancient Turkic groups that appeared here in the era of the Huns; Kipchak tribes of the High Middle Ages; as well as those peoples of the Golden Horde, which later became known as Kazakhs and Uzbeks. We should not forget about the local, Siberian, so to speak, component.
The ethnic core of the Kazan (and wider Volga–Ural) Tatars became the Bulgars, one of the Turkic tribes that operated in the early Middle Ages. Slavic and Finno-Ugric groups were assimilated by them, and in the Horde time Kipchaks and Nogais from the Great Steppe were added to them.
Therefore, the Kazan people are predominantly Caucasians, the Siberian Tatars are a transitional race, however, they have more Mongolian features. Their differences are visually noticeable.
The fact is that the very political construct of the Tatars has a Russian, and even more so a Soviet origin. Simply because when the first censuses began to be conducted in the Russian Empire, ethnography was poorly developed as a science. And somehow it was necessary to keep records of the population.
Therefore, all former Horde members were recorded as Tatars, regardless of who they were and where they came from, from which province and village, how they look and what kind of life they lead. There was no malicious intent in this, especially since the relations between the different groups were quite fraternal, they lived very mixed and the number of common marriages was on top.
But the Soviet government went even further. There was such a general principle that every nation should have the right to self-determination and self-government, a common culture and a common literary language. Many people needed it, but most of all, the Central Asian citizens, who did not feel like a single people at all. But the Tatars also had their own roots.
Since Kazanli are historically the most numerous, Tatarstan became the center of all our Tatars, i.e., not quite the center, but it was their culture that began to be recognized as the basic one. It was then that they began to be called Tatars for the first time. Before that, the general self-designation was either Bulgars or Kazan. They were also designated as part of a single Tatar nation, like the Siberian, Astrakhan and all other Tatars, with the exception of the Crimean Tatars, who are still people of a different culture.
The Soviet era smoothed out many contradictions. Now most Tatars really consider themselves to be one people. Although they remember their own separate history. This was greatly helped by the fact that there have always been many mixed marriages. As Kazan became the main center of culture, the process of Tatar consolidation intensified.
In general, it can be said that the Tatars of Siberia no longer particularly distinguish which of them come from the Volga and who are native Siberians. There is no friction on this basis, but from time to time the issue is raised by the concerned intelligentsia.
Sometimes it is put on view because of the money. Let’s say the Tyumen Region decided to allocate funds for the «development of national culture.» The question arises: who will receive them? Therefore, the organization of Siberian Tatars was founded first, and then the Kazan Tatars. Basically, the main purpose of their activities is to justify the need for their own existence.
However, during the population censuses, a very significant number of Tatars want to be called Siberian. And this means that they still perceive themselves as a separate people.