child born here, and thereby obtained the title porphyrogénnētos (born in the purple) the ultimate accolade of legitimacy for an imperial prince or princess. The concept of a 'purple birth' predated the construction of the chamber, but it gained a literal aspect from the chamber's existence. The porphyry was reputed to have come from Rome and represented a direct link to the ancient origins of Byzantine imperial authority. Constantine also rebuilt the prominent church of Hagia Eirene in Constantinople, which had been badly damaged by the earthquake that hit Constantinople in 740. The building preserves rare examples of iconoclastic church decoration. With the impetus of having fathered numerous offspring, Constantine codified the court titles given to members of the imperial family. He associated only his eldest son, Leo, with the throne as co-emperor (in 751), but gave his younger sons the titles of caesar for the more senior in age and nobelissimos for the more junior. Campaigns against the Arabs In 746, profiting by the unstable conditions in the Umayyad Caliphate, which was falling apart under Marwan II, Constantine invaded Syria and captured Germanikeia (modern Marash, his father's birthplace), and he recaptured the island of Cyprus. He organised the resettlement of part of the local Christian population to imperial territory in Thrace, strengthening the empire's control of this region. In 747 his fleet destroyed the Arab fleet off Cyprus. The same year saw a serious outbreak of plague in Constantinople, which caused a pause in Byzantine military operations. Constantine retired to Bithynia to avoid the disease and, after it had run its course, resettled people from mainland Greece and the Aegean islands in Constantinople to replace those who had perished. In 751 he led an invasion into the new Abbasid Caliphate under As-Saffah. Constantine captured Theodosiopolis (Erzurum) and Melitene (Malatya), which he demolished, and again resettled some of the population in the Balkans. The eastern campaigns failed to secure concrete territorial gains, as there was no serious attempt to retain control of the captured cities, except Camachum (modern Kemah, Erzincan), which was garrisoned. However, under Constantine the Empire had gone on the offensive against the Arabs after over a century of largely defensive warfare. Constantine's major goal in his eastern campaigns seems to have been to forcibly gather up local Christian populations from beyond his borders in order to resettle Thrace. Additionally, the deliberate depopulation of the region beyond the