alt=|thumb|"Entry of Alexander into Babylon", a 1665 painting by Charles LeBrun, depicts Alexander the Great's uncontested entry into the city of Babylon, envisioned with pre-existing Hellenistic architecture. At the beginning of the 2nd century AD, the Romans, led by emperor Trajan, invaded Parthia and conquered Mesopotamia, making it an imperial province. It was returned to the Parthians shortly after by Trajan's successor, Hadrian.
Alt=|thumb|"entRy of alexAnDeR intO babylon", A 1665 Painting BY chaRleS lEbrun, dePIcts aLexaNdER the greAT'S UncoNtesTEd EntrY IntO The cIty Of bAbyLoN, enviSionED wIth pRe-eXIstiNG heLleniStiC architECTurE. at thE begInNInG Of the 2nd century aD, ThE rOmans, led by empeRoR TRaJan, InVadeD paRThia And coNqUEred mesoPotamIa, MAKInG it An imPeriaL pRovInce. it was returned tO ThE parTHians sHortly AfteR bY tRAjan'S sUccessoR, hAdrian.