The Khazars were a Turkic people who lived on the Steppes were Europe and Asia meet. They established the first feudal state in Eastern Europe thus advancing civilization in a land where barbaric tribes still roamed. Their leaders were also Jews who converted out of geopolitical practicality (free from Byzantine Christian and Arabic Muslim cultural pulls). They reigned on the Steppes until 969 when the Rus (proto-Russians) came and destroyed their empire. Rus, Russians, and Mongol assimilated the Khazars until they existed no more as a separate group.
A Russian archaeologist has declared he has found the long lost capital of the Khazars. The city was near the Caspian Sea and along the Silk Road trade route. The city was the only one where the Khazars were allowed to use flame brick, a symbol of permanence in a culture still in a nomadic mindset.
Artifacts from the dig and other Khazar digs are available for viewing on a Russian museum's webpage. One can really see the Turkic nature in the uniforms.