(Not the same as Tatars
"Tartary (Latin: Tartaria) or Great Tartary (Latin: Tartaria Magna) was a historical region but up until the late 18th century it was known as a vast country[1] located in northern and central Asia stretching eastwards from the Caspian Sea and from the Ural Mountains to the Pacific Ocean, inhabited mostly by Turkic peoples."
It appears on several ancient maps, had it's own flag and is even referenced in Frankenstein (lol).
I'm far from discouraging further discussion but the response by u/Kochevnik81 in this thread nicely addresses the identity of Tatars.