Short answers, pulled from the story.
The Tatars are a group of Turkic-speaking peoples found across Eastern Europe and Northern Asia. The largest group, the Volga Tatars, are native to the Volga-Ural region of European Russia, primarily Tatarstan and Bashkortostan. Crimean Tatars are indigenous to Crimea, and Siberian Tatars inhabit three distinct regions of Siberia.
The Persian word tatār, meaning "mounted messenger," entered Arabic in the 13th century in reference to the armies of Genghis Khan. Western European languages added a second r, producing "Tartar," most likely due to an association with Tartarus, the underworld of Greek myth, according to the Oxford English Dictionary.
In May 1944, the USSR State Defense Committee ordered the total deportation of all Crimean Tatars from Crimea. Deportees were transported in cattle trains to Central Asia, primarily Uzbekistan. During the deportation and the first years of exile, 46% of Crimean Tatars died.
The Lipka Tatars were Turkic-speaking Tatars who first settled in the Grand Duchy of Lithuania at the beginning of the 14th century. The Grand Dukes granted every Tatar settler szlachta (nobility) status because of their reputation as skilled warriors. By the 17th century the community numbered roughly 15,000 persons in around 60 villages, and the May Constitution of 1791 gave them representation in the Polish Sejm.
The Crimean Khanate was founded in 1441 when an embassy of Crimean clans invited Haci Giray to rule. He established the Giray dynasty, which governed Crimea until Russia annexed the khanate in 1783, a span of over three centuries.
There are an estimated 5.3 million ethnic Tatars in Russia. Volga Tatars compose 53% of Tatarstan's population.