▁the ▁Middle ▁East ▁tied ▁to ▁the ▁new ▁Roman ▁capital ▁of ▁Constantin ople . ▁The ▁subsequent ▁Fall ▁of ▁the ▁Western ▁Roman ▁Empire ▁therefore , ▁had ▁minimal ▁direct ▁impact ▁on ▁the ▁region . ▁ ▁By z antine ▁Empire ▁( E astern ▁Roman ▁Empire ) ▁ ▁The ▁Eastern ▁Roman ▁Empire , ▁today ▁commonly ▁known ▁as ▁the ▁By z antine ▁Empire , ▁r uling ▁from ▁the ▁B alk ans ▁to ▁the ▁Eu phr ates , ▁became ▁increasing ly ▁defined ▁by ▁and ▁dog m atic ▁about ▁Christian ity , ▁gradually ▁creating ▁religious ▁rif ts ▁between ▁the ▁do ctr ines ▁dict ated ▁by ▁the ▁establishment ▁in ▁Constantin ople ▁and ▁bel ie vers ▁in ▁many ▁parts ▁of ▁the ▁Middle ▁East . ▁By ▁this ▁time , ▁Greek ▁had ▁become ▁the ▁' ling ua ▁fran ca ' ▁of ▁the ▁region , ▁although ▁eth nic ities ▁such ▁as ▁the ▁Sy ri acs ▁and ▁the ▁Heb rew ▁continued ▁to ▁exist . ▁Under ▁By z antine / G reek ▁rule ▁the ▁area ▁of ▁the ▁Lev ant ▁met ▁an ▁era ▁of ▁stability ▁and ▁prosper ity . ▁ ▁Post - class ical ▁Middle ▁East ▁ ▁Pre - I sl am ▁In ▁the ▁ 5 th ▁century , ▁the ▁Middle ▁East ▁was ▁separated ▁into ▁small , ▁weak ▁states ; ▁the ▁two ▁most ▁prominent ▁were ▁the ▁S as an ian ▁Empire ▁of ▁the ▁Pers ians ▁in ▁what ▁is ▁now ▁Iran ▁and ▁Ira q , ▁and ▁the ▁By z antine ▁Empire ▁in ▁An atol ia ▁( mod ern - day ▁Turkey ). ▁The ▁By z ant ines ▁and ▁S as