Complex sentence: The Bulgars are first mentioned in the 4th century in the vicinity of the North Caucasian steppe, although scholars speculate that their history may go back to the Central Asian nomadic confederations, Образуване на българската държава.
Split into simpler sentences: The Bulgars are first mentioned in the 4th century in the vicinity of the North Caucasian steppe. Although scholars often suggest their ultimate origins traces back to the Central Asian nomadic confederations, Образуване на българската държава.