Byzantium and the Arabs in the Sixth Century is devoted to frontier studies and to the structures of the Arab federates of Byzantium. It deals mainly with the Ghassanids of Oriens in the sixth century, a time of transition from Late Antiquity to the Middle Ages. The focus of this study is on the military, religious, and civil structures of the Ghassanids. The detailed study of these buildings contributes to our understanding of Byzantine provincial art and architecture in Oriens, as they were adopted by the federate Arabs and later adapted to their own use. As monuments of Christian architecture, these federate structures constitute the missing link in the development of Arab architecture in the region—the link between the earlier pagan (Nabataean and Palmyrene) and later Muslim (Umayyad).