. ▁O pp osing ▁them ▁were ▁the ▁S ass an id ▁Pers ians , ▁al lied ▁with ▁the ▁Av ars . ▁The ▁war ▁was ▁fought ▁against ▁the ▁background ▁of ▁the ▁last ▁By z antine - S ass an id ▁War ▁and ▁served ▁as ▁a ▁pre l ude ▁to ▁the ▁dram atic ▁events ▁that ▁changed ▁the ▁balance ▁of ▁powers ▁in ▁the ▁Middle ▁East ▁for ▁centuries ▁to ▁come ▁( B attle ▁of ▁N ine ve h , ▁Islam ic ▁con quest ▁of ▁Pers ia ). ▁ ▁Background ▁ ▁Following ▁the ▁First ▁Sie ge ▁of ▁Constantin ople ▁by ▁the ▁Av ars ▁and ▁Pers ians , ▁the ▁be le ag uer ed ▁By z antine ▁Emperor ▁Her ac lius ▁found ▁himself ▁polit ically ▁isolated . ▁He ▁could ▁not ▁rely ▁on ▁the ▁Christian ▁Armen ian ▁pot ent ates ▁of ▁Trans c au cas ia , ▁since ▁they ▁were ▁brand ed ▁as ▁her et ics ▁by ▁the ▁Orth odox ▁Church , ▁and ▁even ▁the ▁king ▁of ▁I ber ia ▁preferred ▁to ▁be friend ▁the ▁religious ly ▁toler ant ▁Pers ians . ▁Again st ▁this ▁dis mal ▁background , ▁he ▁found ▁a ▁natural ▁al ly ▁in ▁T ong ▁Y ab g hu . ▁Ear lier ▁in ▁ 5 6 8 , ▁the ▁Tur ks ▁under ▁Ist ä mi ▁had ▁turned ▁to ▁By z ant ium ▁when ▁their ▁relations ▁with ▁Pers ia ▁sou red ▁over ▁commerce ▁issues . ▁Ist ä mi ▁sent ▁an ▁emb ass y ▁led ▁by ▁the ▁S og d ian ▁diplom at ▁Man iah ▁directly ▁to ▁Constantin ople