Historically, the word "Tatar" might have referred to the Tatar confederation, which eventually became part of the Mongol Empire when Genghis Khan joined the various Eurasian steppe tribes into one empire. The term "Tatars" was spelled as "Tartars" on occasion. In the past, this term was used to refer to anyone coming from North and Central Asia dominated by many predominantly Turco-Mongol empires and kingdoms. Neighbouring non-Turkic peoples called any Turkic-speaking people Tatar. Nowadays, this term is used to refer to certain Turkic peoples.