. ▁The ▁By z ant ines ▁experienced ▁extensive ▁territorial ▁loss . ▁However , ▁while ▁the ▁inv ading ▁Arab s ▁gained ▁strong ▁control ▁in ▁the ▁Middle ▁East ▁and ▁Africa , ▁further ▁con quest s ▁in ▁Western ▁Asia ▁were ▁halt ed . ▁The ▁focus ▁of ▁the ▁By z antine ▁Empire ▁shift ed ▁from ▁the ▁western ▁recon quest s ▁of ▁Justin ian ▁to ▁a ▁primarily ▁def ensive ▁position , ▁against ▁the ▁Islam ic ▁arm ies ▁on ▁its ▁eastern ▁borders . ▁Without ▁By z antine ▁inter ference ▁in ▁the ▁emer ging ▁Christian ▁states ▁of ▁western ▁Europe , ▁the ▁situation ▁gave ▁a ▁huge ▁stim ulus ▁to ▁fe ud al ism ▁and ▁economic ▁self - su ffic iency . ▁ ▁The ▁view ▁of ▁modern ▁histor ians ▁is ▁that ▁one ▁of ▁the ▁most ▁important ▁effects ▁was ▁the ▁stra in ▁it ▁put ▁on ▁the ▁relationship ▁between ▁Rome ▁and ▁By z ant ium . ▁While ▁fighting ▁for ▁surv ival ▁against ▁the ▁Islam ic ▁arm ies , ▁the ▁Empire ▁was ▁no ▁longer ▁able ▁to ▁provide ▁the ▁protection ▁it ▁had ▁once ▁offered ▁to ▁the ▁Pap acy ; ▁worse ▁still , ▁according ▁to ▁Thomas ▁Wood s , ▁the ▁Em per ors ▁" rout in ely ▁interven ed ▁in ▁the ▁life ▁of ▁the ▁Church ▁in ▁areas ▁lying ▁clearly ▁beyond ▁the ▁state ' s ▁compet ence ". ▁The ▁Icon oc last ▁controvers y ▁of ▁the ▁ 8 th ▁and ▁ 9 th ▁centuries ▁can ▁be ▁taken ▁as ▁a ▁key ▁factor ▁" which ▁drove ▁the ▁Latin ▁Church ▁into ▁the ▁arms ▁of ▁the ▁Fran ks ." ▁Thus ▁it ▁has