Tartary is a vast country in the northern parts of Asia, bounded by Siberia on the north and west: this is called Great Tartary. Tartary was a country with its own flag, its own government, its own language and its own place on maps, especially predating the second half of the 19th century. Its territory was huge, but somehow quietly incorporated into Russia, China, and some other countries.
Genghis Khan was the founder and first Great Khan 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.