In 552 when the Juan-juan confederacy in Mongolia was destroyed by Chinese armies cooperating with Turks, the Turks created a new steppe empire reaching from Turkestan to India and Manchuria.
Another Turkish army invaded the Caucasus in 576, then split apart from the main power and established the first independent Turkish Khanate in Europe - known as the Khazar Khanate which spread over southern Russia.
By the second half of the 8th century their empire reached the peak of its power. In the middle of the 8th century the ruling classes adopted Judaism as their religion. By the 10th century the Khazar empire declined and was finally crushed by the Russian rulers of Kiev.