170 Reviews Shahid, I., Rome and the Arabs: a prolegomenon to the study of Byzantium and the Arabs (Dumbartons Oaks Library and Collection), Washington, Dumbarton Oaks, 1984; cloth; pp. xxxi, 193; 4 maps; R. R. P. £25.00; Idem, Byzantium and the Arabs in thefourth century (Dumbarton Oaks Research Library and Collection), Washington, Dumbarton Oaks, 1984; cloth; pp. xxiii, 628; 8 maps, 2 plates; R. R. P. £32.00. With these two studies Irfan Shahid has embarked on an important and ambitious project that few have the skills to contemplate, let alone bring to a successful conclusion. He has set himself the task of understanding how it was that in 636 at the Battle of the Yarmuk the Arab armies inflicted a defeat of such magnitude on the Byzantine forces under the emperor Heraclius that the territories lost then were never recovered. This battle was a turning point in the development of the Byzantine state, which from then on was cut off from the granaries of Egypt (a vital element in the provisioning of the capital Constantinople), the Christian communities of Syria and the Holy Places of Jerusalem and from henceforth had to contend with a series of hostile and invasive rulers in areas that had been for centuries within the Roman sphere of influence. Shahid quiterightlyconsiders that the answers he is seeking cannot be sought only in the events of the years around 636. Byzantine-Arab relations need to be viewed over the long term and Shahid has allowed himself three large volumes (on the fourth, fifth and sixth centuries) and a substantial introduction in which to do this. The volumes reviewed here represent the introduction and the discussion of the fourth century. There is no doubt that this is a subject for which there is a need for a modern overview that takes into account recent epigraphical and archaeological investigations. Vasiliev's work on the Arabs, now in need of revision, dealt with the ninth and tenth centuries, which one suspects Shahid also has in his sights, and Canard never produced a work of synthesis on this period. In many ways the most useful surveys have been those in, for example, the Dictionnaire a"Histoire et de Giographie Ecclisiastique (s.v. Arable). The historian faces formidable problems, especially for the period covered by these volumes. The sources are scanty. There is no continuous narrative that makes Arab-Roman/Arab-Byzantine relations a major concern. References to Arabs in the Byzantine sources have to be extracted from Ammianus, Zosimus and the ecclesiastical historians, and the sum total of passages is challengingly smaU, whde the Arabic sources — where interest in this period by later Islamic writers was not strong — are equally fitful. Then the invaluable epigraphical material for this period comes down to a bare handful of examples. Shahid brings to this material an admirable range of expertise. He is one of the few who is at ease with the Arabic material as well as with the Latin and Greek and his training as a historian of late antiquity enables him to bring out to the full Reviews 111 the legal and administrative implications of stray phrases in Ammianus, for example, or the Notitia Dignitatum. Because of the nature of the material Shahid devotes more space to analysis than exposition though the final section of each book consists of a comparatively brief narrative of the sequence of events whose political, military and economic interrelationship has been established in the previous pages. Points that are of especial concern to Shahid are the reasons for the usually derogatory image of the Arabs in Byzantine writers and the interestingly strong evidence for the extent of the early Christianization of the Arabs. The strengths of these books are that they are Arabo-centric. It is salutary to read Shahid's analyses, for example, of the evidence for Arab tribal structures and federations in the third and fourth centuries, of the extent to which the sedentary and nomad groups were Romanized, of the role played by Arab troops in the frontier zones, and of the extent to which Arab blood ran in the veins of the Severan House. The evidence is clear (cf. G. W...