▁under ▁Z hang ▁X ia os ong ▁to ▁Fer gh ana . ▁He ▁defeated ▁Al ut ar ▁and ▁the ▁Arab ▁occupation ▁force ▁at ▁Nam ang an ▁and ▁re installed ▁the ▁ik h sh id ▁on ▁the ▁throne . ▁The ▁Chinese ▁defeated ▁the ▁Um ay y ad ▁inv aders ▁at ▁the ▁Battle ▁of ▁A ks u ▁( 7 1 7 ), ▁forcing ▁the ▁Um ay y ad ▁commander , ▁Al - Y ash k uri , ▁and ▁his ▁army ▁to ▁fle e ▁to ▁T ash k ent . ▁ ▁C ali ph ate ▁of ▁U mar ▁II ▁Sul ay man ▁was ▁succeeded ▁by ▁his ▁cousin , ▁U mar ▁ibn ▁Abd ▁al - Az iz ▁( 7 1 7 – 7 2 0 ), ▁whose ▁position ▁among ▁the ▁Um ay y ad ▁cal i ph s ▁is ▁somewhat ▁unusual . ▁He ▁is ▁the ▁only ▁Um ay y ad ▁r uler ▁to ▁have ▁been ▁recognized ▁by ▁subsequent ▁Islam ic ▁tradition ▁as ▁a ▁genu ine ▁cal i ph ▁( k hal ifa ) ▁and ▁not ▁merely ▁as ▁a ▁world ly ▁king ▁( mal ik ). ▁ ▁U mar ▁is ▁hon oured ▁for ▁his ▁attempt ▁to ▁resolve ▁the ▁fis cal ▁problems ▁att endant ▁upon ▁conversion ▁to ▁Islam . ▁During ▁the ▁Um ay y ad ▁period , ▁the ▁majority ▁of ▁people ▁living ▁within ▁the ▁cal i ph ate ▁were ▁not ▁Muslim , ▁but ▁Christian , ▁Jewish , ▁Z oro ast rian , ▁or ▁members ▁of ▁other ▁small ▁groups . ▁These ▁religious ▁communities ▁were ▁not ▁forced ▁to ▁convert ▁to ▁Islam