By the time of Theodosius I, the organisation of the Imperial Church had aligned to the civil administration of the empire. Every city had a bishop, every province had a metropolitan, and every civil diocese had an exarch.Bury, J. B. History of the Later Roman Empire From the Death of Theodosius I to the Death of Justinian Vol I (1958), p. 64 At the level of the Praetorian Prefectures sat the five Patriarchates. The Bishop of Rome's authority extended over the whole western or Latin half of the Empire, and included the Praetorian prefecture of Illyricum. The Patriarchate of Constantinople had oversight over the civil dioceses of Thrace, Pontus, and Asia. The Patriarchate of Alexandria corresponded to the Diocese of Egypt. The Patriarchate of Antioch had jurisdiction over the majority of the Praetorian prefecture of the East, while the smaller Patriarchate of Jerusalem dominated the three Palestinian provinces.Bury, J. B. History of the Later Roman Empire From the Death of Theodosius I to the Death of Justinian Vol I (1958), pp. 64–65
