▁of ▁division ▁of ▁labor , ▁as ▁well ▁as ▁lay ing ▁the ▁foundation ▁for ▁the ▁fields ▁of ▁astronom y ▁and ▁mathematics . ▁However , ▁its ▁emp ires ▁also ▁introduced ▁rig id ▁social ▁strat ification , ▁sla very , ▁and ▁organized ▁war fare . ▁ ▁C rad le ▁of ▁civil ization , ▁S umer ▁and ▁A kk ad ▁The ▁earliest ▁civil izations ▁in ▁history ▁were ▁established ▁in ▁the ▁region ▁now ▁known ▁as ▁the ▁Middle ▁East ▁around ▁ 3 5 0 0 ▁BC ▁by ▁the ▁S umer ians , ▁in ▁Mes op ot am ia ▁( I ra q ), ▁widely ▁regarded ▁as ▁the ▁cr ad le ▁of ▁civil ization . ▁The ▁S umer ians ▁and ▁the ▁A kk ad ians , ▁and ▁later ▁Bab yl oni ans ▁and ▁Ass y ri ans ▁all ▁fl our ished ▁in ▁this ▁region . ▁ ▁" In ▁the ▁course ▁of ▁the ▁fourth ▁mill en ni um ▁BC , ▁city - states ▁developed ▁in ▁southern ▁Mes op ot am ia ▁that ▁were ▁domin ated ▁by ▁tem ples ▁whose ▁pri ests ▁represented ▁the ▁cities ' ▁patron ▁de ities . ▁The ▁most ▁prominent ▁of ▁the ▁city - states ▁was ▁S umer , ▁which ▁gave ▁its ▁language ▁to ▁the ▁area , ▁[ pres umably ▁the ▁first ▁written ▁language ,] ▁and ▁became ▁the ▁first ▁great ▁civil ization ▁of ▁man kind . ▁About ▁ 2 3 4 0 ▁BC , ▁S arg on ▁the ▁Great ▁( c . ▁ 2 3 6 0 – 2 3 0 5 ▁BC ) ▁un ited ▁the ▁city -