▁ra ids ▁into ▁still - By z antine ▁Asia ▁Minor , ▁twice ▁bes ie ge ▁the ▁By z antine ▁capital ▁of ▁Constantin ople , ▁and ▁conquer ▁the ▁By z antine ▁Ex arch ate ▁of ▁Africa . ▁The ▁situation ▁did ▁not ▁stabil ize ▁until ▁after ▁the ▁failure ▁of ▁the ▁Second ▁Arab ▁Sie ge ▁of ▁Constantin ople ▁in ▁ 7 1 8 , ▁when ▁the ▁T aur us ▁Mountains ▁on ▁the ▁eastern ▁rim ▁of ▁Asia ▁Minor ▁became ▁established ▁as ▁the ▁mut ual , ▁heavily ▁fort ified ▁and ▁largely ▁dep op ulated ▁front ier . ▁Under ▁the ▁Abb as id ▁Empire , ▁relations ▁became ▁more ▁normal , ▁with ▁emb ass ies ▁ex changed ▁and ▁even ▁periods ▁of ▁tr uce , ▁but ▁conflict ▁remained ▁the ▁norm , ▁with ▁almost ▁annual ▁ra ids ▁and ▁counter - ra ids , ▁spons ored ▁either ▁by ▁the ▁Abb as id ▁government ▁or ▁by ▁local ▁r ul ers , ▁well ▁into ▁the ▁ 1 0 th ▁century . ▁ ▁During ▁the ▁first ▁centuries , ▁the ▁By z ant ines ▁were ▁usually ▁on ▁the ▁def ensive , ▁and ▁avoided ▁open ▁field ▁batt les , ▁prefer ring ▁to ▁retre at ▁to ▁their ▁fort ified ▁strong holds . ▁Only ▁after ▁ 7 4 0 ▁did ▁they ▁begin ▁to ▁launch ▁their ▁ra ids ▁in ▁an ▁attempt ▁to ▁combat ▁the ▁Arab s ▁and ▁take ▁the ▁lands ▁they ▁had ▁lost , ▁but ▁still ▁the ▁Abb as id ▁Empire ▁was ▁able ▁to ▁ret ali ate ▁with ▁often ▁massive ▁and ▁destruct ive ▁invas ions ▁of ▁Asia ▁Minor . ▁With ▁the