Baghdad replaced both Damascus and Seleucia-Ctesiphon as the key city of the Middle East. In the battle for prominence among the various factions of Christianity, that shift eastwards would inevitably favour the Dyophysite ‘Church of the East’ against the Melchites and Miaphysites, and the Abbasids gave an unprecedented official jurisdiction to the Dyophysite patriarch over all Christians in their caliphate, which stretched from Egypt into Central Asia.
