▁the ▁origin ▁of ▁the ▁cl an ▁probably ▁was ▁Turk ic . ▁This ▁proposition ▁was ▁suggested ▁by ▁Mik h ail ▁Art am on ov , ▁and ▁was ▁prompt ed ▁by ▁Lev ▁G um ile v ▁( 1 9 6 7 ), ▁imp lying ▁there ▁may ▁be ▁made ▁an ▁association ▁of ▁the ▁D ulo ▁cl an ▁with ▁the ▁five ▁Du olu ▁( or ▁To - lu ) ▁tribes ▁of ▁the ▁Western ▁Tur ks . ▁The ▁First ▁Turk ic ▁Kh agan ate ▁( 5 5 2 – 5 8 1 ) ▁was ▁during ▁the ▁Gö kt ür k ▁civil ▁war ▁( 5 8 1 – 5 9 3 ) ▁divided ▁into ▁Western ▁and ▁Eastern ▁Kh agan ate . ▁The ▁Western ▁was ▁led ▁by ▁O no q ▁( ten ▁ar rows ), ▁the ▁five ▁Du olu ▁and ▁five ▁N ush ib i ▁tribes . ▁Many ▁modern ▁histor ians ▁consider ▁that ▁the ▁first ▁historical ▁Bulgar ▁r uler ▁Kub rat ▁belonged ▁to ▁the ▁D ulo ▁cl an ▁of ▁the ▁Western ▁Tur ks ▁- ▁the ▁so - called ▁al liance ▁On og urs ▁Bulg ars . ▁ ▁Some ▁histor ians ▁have ▁even ▁identified ▁the ▁Western ▁q ag han ▁Moh edu o ▁( K ül üg ▁Sib ir ) ▁with ▁Or g ana , ▁the ▁mat ernal ▁uncle ▁of ▁Kub rat . ▁Acc ur ately ▁or ▁not , ▁it ▁still ▁points ▁to ▁the ▁rival ry ▁between ▁the ▁Bulg ars , ▁led ▁by ▁Kub rat ▁from ▁the ▁D ulo ▁cl an , ▁and ▁the ▁Kh az ars , ▁led ▁by ▁the ▁Ash