▁sought ▁support ▁for ▁a ▁" member ▁of ▁the ▁family " ▁of ▁Muhammad , ▁without ▁making ▁explicit ▁mention ▁of ▁the ▁Abb as ids . ▁These ▁miss ions ▁met ▁with ▁success ▁both ▁among ▁Arab s ▁and ▁non - A rab s ▁( ma w ali ), ▁although ▁the ▁latter ▁may ▁have ▁played ▁a ▁particularly ▁important ▁role ▁in ▁the ▁growth ▁of ▁the ▁movement . ▁ ▁Ar ound ▁ 7 4 6 , ▁Ab u ▁Muslim ▁assumed ▁leadership ▁of ▁the ▁Hash imi y ya ▁in ▁Kh uras an . ▁In ▁ 7 4 7 , ▁he ▁successfully ▁initi ated ▁an ▁open ▁revol t ▁against ▁Um ay y ad ▁rule , ▁which ▁was ▁carried ▁out ▁under ▁the ▁sign ▁of ▁the ▁black ▁flag . ▁He ▁soon ▁established ▁control ▁of ▁Kh uras an , ▁exp elling ▁its ▁Um ay y ad ▁governor , ▁Nas r ▁ibn ▁Say yar , ▁and ▁dispatch ed ▁an ▁army ▁west wards . ▁K uf a ▁fell ▁to ▁the ▁Hash imi y ya ▁in ▁ 7 4 9 , ▁the ▁last ▁Um ay y ad ▁strong hold ▁in ▁Ira q , ▁Was it , ▁was ▁placed ▁under ▁sie ge , ▁and ▁in ▁November ▁of ▁the ▁same ▁year ▁Ab ul ▁Abb as ▁as - S aff ah ▁was ▁recognized ▁as ▁the ▁new ▁cal i ph ▁in ▁the ▁mos que ▁at ▁K uf a . ▁At ▁this ▁point ▁Mar wan ▁mobil ized ▁his ▁troops ▁from ▁Har ran ▁and ▁advanced ▁toward ▁Ira q . ▁In ▁January ▁ 7 5 0 ▁the ▁two ▁forces ▁met ▁in ▁the ▁Battle ▁of ▁the