Syrian, Mesopotamian, Egyptian and Libyan provinces, formed the Diocese of the East (in the late 4th century the African component was split off as Diocese of Egypt), part of the praetorian prefecture of the East, the rich bulk of the eastern Roman Empire. Cilicia proper remained under East Roman (Byzantine) control until the early 8th century, when it was conquered by the Umayyad Caliphate and became part of the Islamic borderlands (thughur) with the Romans. The region had, however, been almost completely depopulated already since the middle of the 7th century and formed a no man's land between the Romans and the Caliphate. The western parts of the old province of Cilicia remained in Roman hands and became part of the Cibyrrhaeot Theme. The status quo would remain unchanged for over 260 years before Cilicia was eventually reconquered for the Romans in the 950s and 960s by Nikephoros Phokas and John Tzimiskes. See also List of Roman governors of Cilicia References Sources Pilhofer, Philipp. 2018. Das frühe Christentum im kilikisch-isaurischen Bergland. Die Christen der Kalykadnos-Region in den ersten fünf Jahrhunderten (Texte und Untersuchungen zur Geschichte der altchristlichen Literatur, vol. 184). Berlin/Boston: De Gruyter (), p. 25–49. Broughton, T. Robert S., The Magistrates of the Roman Republic, Vol. I (1951) Smith, William, Dictionary of Greek and Roman Biography and Mythology, Vol III (1867) Smith, William, Dictionary of Greek and Roman Geography (1854) Provinces of the Roman Empire Roman provinces in Anatolia Former countries in Western Asia States and territories established in the 1st century BC States and territories disestablished in the 7th century 1st-century BC establishments in the Roman Republic 1st-century BC establishments 7th-century disestablishments in the Byzantine Empire