Tatars (Tatar: Tatarlar / Татарлар, sometimes spelled Tartars) are a Turkic people, numbering around 7 million. The majority of Tatars live in the Russian Federation, with a population of 5.5 million, 2 million of which in the republic of Tatarstan, 1 million in the republic of Bashkortostan and other 2.5 million in different regions of Russia. Significant minority populations are found in Uzbekistan, Kazakhstan, Kyrgyzstan and Ukraine.

The Tatars originated with the Tatar confederation in the north-eastern Gobi desert in the 5th century. After subjugation in the 9th century by the Khitans, they migrated southward. In the 13th century Mongol Empire, they were subjugated under Genghis Khan and reassigned once again particularly by his son Jochi. Under the leadership of his grandson Batu Khan, they moved westwards, forming part of the Golden Horde which dominated the Eurasian steppe during the 14th and 15th centuries. In Europe, they were assimilated by the local populations or their name spread to the conquered peoples: Kipchaks, Kimaks and others; and elsewhere with Uralic-speaking peoples, as well as with remnants of the ancient Greek colonies in the Crimea and Caucasians in the Caucasus.

Tatars are a Turkic ethnic group numbering 6,7 million in the late 20th Century, including all subgroups of Tatars, such as Volga Tatars, and Lipka Tatars. Russia is home to the majority of ethnic Tatars, with a population of around 5,500,000. Uzbekistan, Kazakhstan, Ukraine, Tajikistan, Kyrgyzstan, Turkmenistan, and Azerbaijan also each have populations greater than 30,000.

Crimean Tatars (sg. Qırımtatar, pl. Qırımtatarlar) or Crimeans (sg. Qırım, Qırımlı, pl. Qırımlar, Qırımlılar) are a Turkic ethnic group that originally resided in Crimea. They speak the Crimean Tatar language. They are not to be confused with the Volga Tatars.

In modern times, in addition to living in Crimea, Ukraine, there is a large diaspora of Crimean Tatars in Turkey, Romania, Bulgaria, Uzbekistan, Western Europe, the Middle East and North America, as well as small communities in Finland, Lithuania, Russia, Belarus and Poland. (See Crimean Tatar diaspora)

Today, more than 240,000 Crimean Tatars live in Crimea and about 150,000 remain in exile in Central Asia, mainly in Uzbekistan. There is an unspecified number of people of Crimean Tatar origin living in Turkey, descendants of those who emigrated in the 19th and early 20th centuries. In the Dobruja region straddling Romania and Bulgaria, there are more than 27,000 Crimean Tatars: 24,000 on the Romanian side, and 3,000 on the Bulgarian side^{[citation needed]}.

Genghis Khan (/ˈɡɛŋɡɪs ˈkɑːn/ or /ˈdʒɛŋɡɪs ˈkɑːn/,Mongol: [tʃiŋɡɪs xaːŋ] ( listen); 1162? – August 1227), born Temujin, was the founder and Great Khan (emperor) of the Mongol Empire, which became the largest contiguous empire in history after his death.

He came to power by uniting many of the nomadic tribes of northeast Asia. After founding the Mongol Empire and being proclaimed "Genghis Khan", he started the Mongol invasions that resulted in the conquest of most of Eurasia. These included raids or invasions of the Kara-Khitan Khanate, Caucasus, Khwarezmid Empire, Western Xia and Jin dynasties. These campaigns were often accompanied by wholesale massacres of the civilian populations – especially in Khwarezmia. By the end of his life, the Mongol Empire occupied a substantial portion of Central Asia and China.

Before Genghis Khan died, he assigned Ögedei Khan as his successor and split his empire into khanates among his sons and grandsons. He died in 1227 after defeating the Western Xia. He was buried in an unmarked grave somewhere in Mongolia at an unknown location. His descendants went on to stretch the Mongol Empire across most of Eurasia by conquering or creating vassal states out of all of modern-day China, Korea, the Caucasus, Central Asian countries, and substantial portions of modern Eastern Europe, Russia and the Middle East. Many of these invasions resulted in the large-scale slaughter of local populations, which have given Genghis Khan and his empire a fearsome reputation in local histories.