ra , ▁populated ▁by ▁the ▁Arab ▁imm igr ants ▁and ▁troops ▁who ▁arrived ▁during ▁the ▁con quest ▁of ▁Ira q ▁in ▁the ▁ 6 3 0 s – 6 4 0 s , ▁res ented ▁the ▁transition ▁of ▁power ▁to ▁Sy ria . ▁They ▁remained ▁divided , ▁non eth eless , ▁as ▁both ▁cities ▁competed ▁for ▁power ▁and ▁influence ▁in ▁Ira q ▁and ▁its ▁eastern ▁dependencies ▁and ▁remained ▁divided ▁between ▁the ▁Arab ▁trib al ▁nob ility ▁and ▁the ▁early ▁Muslim ▁converts , ▁the ▁latter ▁of ▁whom ▁were ▁divided ▁between ▁the ▁pro - Al ids ▁( loy al ists ▁of ▁Ali ) ▁and ▁the ▁K har ij ites , ▁who ▁followed ▁their ▁own ▁strict ▁interpretation ▁of ▁Islam . ▁The ▁cal i ph ▁applied ▁a ▁decent ral ized ▁approach ▁to ▁gover ning ▁Ira q ▁by ▁for ging ▁al li ances ▁with ▁its ▁trib al ▁nob ility , ▁such ▁as ▁the ▁K uf an ▁leader ▁al - A sh ' ath ▁ibn ▁Q ays , ▁and ▁entr ust ing ▁the ▁administration ▁of ▁K uf a ▁and ▁Bas ra ▁to ▁highly ▁experienced ▁members ▁of ▁the ▁Th a q if ▁tribe , ▁al - M ug hi ra ▁ibn ▁Sh u ' ba ▁and ▁the ▁latter ' s ▁prote ge ▁Z iy ad ▁ibn ▁Ab i hi ▁( wh om ▁Mu ' aw i ya ▁adopted ▁as ▁his ▁half - bro ther ), ▁respectively . ▁In ▁return ▁for ▁recogn izing ▁his ▁su zer ain ty , ▁maintain ing ▁order ▁and ▁the ▁forward ing ▁of ▁a ▁relatively ▁token ▁portion