ulo ▁cl an ▁are ▁not ▁known ▁precisely , ▁and ▁there ▁are ▁many ▁theories ▁about ▁their ▁origin . ▁It ▁is ▁generally ▁considered ▁that ▁they ▁- ▁or ▁at ▁least ▁the ▁el ite ▁cas te ▁- ▁is ▁int imately ▁related ▁to ▁the ▁origin ▁and ▁activity ▁of ▁the ▁H uns ▁and ▁Western ▁Turk ic ▁Kh agan ate . ▁Part icular ly , ▁it ▁is ▁said ▁that ▁the ▁D ulo ▁desc ended ▁from ▁the ▁r ul ers ▁of ▁Great ▁Bulg aria , ▁which ▁was ▁founded ▁by ▁Khan ▁As par uk h ' s ▁( 6 7 9 – 7 0 0 ) ▁father ▁on ▁the ▁ste pp es ▁of ▁Ukraine . ▁This ▁state ▁was ▁a ▁central ized ▁mon archy ▁from ▁its ▁in ception , ▁unlike ▁previous ▁Hun no - T urk ic ▁political ▁entities , ▁which ▁were ▁trib al ▁conf eder ations . ▁ ▁The ▁royal ▁family ▁and ▁r ul ers ▁of ▁Old ▁Great ▁Bulg aria ▁( 6 3 2 – 6 6 8 ) ▁and ▁the ▁first ▁half ▁of ▁the ▁First ▁Bulgar ian ▁Empire ▁( 6 8 1 – 1 0 1 8 ), ▁in ▁their ▁prince ▁lists ▁( N om inal ia ▁of ▁the ▁Bulgar ian ▁k h ans ) ▁claimed ▁through ▁Ir nik , ▁who ▁was ▁probably ▁related ▁to ▁or ▁was ▁Att ila ' s ▁son ▁Er nak ▁himself , ▁or ▁at ▁least ▁of ▁Att il id ▁descent . ▁During ▁the ▁pag an ▁period , ▁the ▁succession ▁of ▁cl an ▁leadership ▁was ▁based ▁on ▁trad itions ▁brought ▁over ▁to ▁the ▁B alk ans ▁from ▁the