The Khazar Empire was a semi-nomadic confederation of states that appeared in the early fifth century in the northern caucasus near to the Uralic Urheimat in the Volga River. Speaking a Turkic language, they annexed a large part of the Caucasus and the Aral area (including the civilised Kingdom of Iberia) before collapsing to Mordvin and Persian troops, losing much land to the Mordvins in the north and to a new kingdom of Iberia before becoming a Sassanid vassal. The Empire was notable for its early conversion to Judaism.