In 180/796 the caliph Hārūn al-Rashīd left Iraq and settled in modern-day Syria at Raqqa, today most famous as the one-time capital of Da‛ish. In the end he stayed there twelve years until 192/808, when he departed to deal with problems in Khurāsān, and of course he died on the journey the following year. A number of reasons have been proposed for the move to Raqqa. There was the problem of instability in Syria, and again the question of a base for the planned invasions of Byzantine Anatolia – Raqqa was constituted the main city of the ʿAw ā ṣim, the back-province of the thugh ū r facing Byzantium. But in the end the location of Raqqa also corresponded well with Hārūn's personal tastes. The wide open spaces of the Jazīra appealed to Arab taste, as with the Umayyad caliph Hishām b. ʿAbd al-Malik at Rusafa. As Kennedy notes, Hārūn never lived in Baghdad, and moved around a number of times.

Islamic Raqqa had been founded in the reign of al-Manṣūr under the direction of Hārūn's father, al-Mahdī in 155/771–2. The new city of al-Rāfiqa was said to be a copy of Manṣūr's Round City in Baghdad, though in fact rather horse-shoe shaped, placed next to the Graeco-Roman city of Callinicum, and intended for a garrison of Khurāsāniyya, the Abbasid troops. This book is about the settlement the caliph built there outside the walls of al-Rāfiqa, a sprawling mass of buildings around the building identified as the caliphal palace, and north of the walled city. Until the 1970s the site was well preserved, the lines of unfired earth walls being quite visible on the surface (the same is not true inside the Abbasid walls, where frequent rebuilding has confused the plan). Unfortunately, the construction of the Tabqa dam, and particularly the rising lake water in 1974, drove the agricultural population out of the river valley, and they settled round the modern city of Raqqa, building over al-Rāfiqa, and the majority of the caliphal residence. Essentially, therefore, tackling a study of this settlement is a question of older air-photos and satellite images, showing what once existed, together with a more detailed report on the parts that could still be excavated.

Indeed, from 1981 to 1988, Michael Meinecke, then director of the Deutsches Archäologisches Institut in Damascus, led a rescue effort to study what could still be recovered, and the author was a member of that team. In fact the work is a publication of the author's PhD thesis, defended in 2012. The author is an architect by training, and that shows in the work.

The work starts with a general summary of the excavations before 1970, including the Syrian excavations of the 1950s published by Nasib Saliby in Volume III of the Raqqa publication series. This is followed only then by a chapter on the textual historical data, which is treated as fairly secondary. In principle one should be able to say a fair amount about the court of Hārūn at Raqqa, even if there is not much in the texts on the description of the settlement itself. But the opportunity is not taken. The history from texts (but not the life of the court) was treated in Raqqa II, Die islamische Stadt, and the author may not have felt the need to develop the theme.

The main body of the work is effectively a detailed excavation report and architectural reconstruction of the buildings excavated by the DAI mission in the 1980s, that is four sites (Ostpalast, Ostkomplex, Nordkomplex, and Nordostkomplex), but with only a brief reference to what was found in them. Although the typology of ceramics was treated in Raqqa I, it would have been interesting to see what the location of finds told us about life in the buildings excavated, as indeed the distribution of finds in the excavations of the 1950s by Saliby, even if not directly addressed in that publication, was very informative. Finally, there is a drawing together of the threads on the architecture and planning of the buildings. The work is excellently illustrated, with 105 figures, 60 plates, and five foldout plans in a pocket.

It is a pity that the work is essentially an excavation report on the four sites excavated, with the remainder being secondary, rather than a balanced overall evaluation of the caliphal settlement. The building identified as the caliphal palace is hardly mentioned at all, no doubt because only one sondage was excavated there in 1944 before the site was destroyed by the incoming settlers. The Syrian excavations published by Saliby likewise receive only a summary mention in this volume, although they are of fascinating historical importance as one or more of them should be the residence of the Barmakids, the viziral family from Balkh, of such political importance in the early reign of Hārūn. The racecourse is not mentioned at all – Siegel had already published an article on it in 2010 (“The racecourse at ar-Raqqa/ar-Rafiqa (Syria)”, Zeitschrift für Orient-Archäologie 3, 2010, 130–41) – but one would have expected a short chapter to make the treatment of the settlement more comprehensive.

The greater problem, which is only approached to a small degree, is: how did the settlement function? There are zoning maps (Taf. 11–12) but these are not very detailed. What was the purpose of all the buildings which are not obviously residences? Very little is said about the buildings which were not excavated. It is unfortunate that a larger body of comparable material at Samarra was only published while Siegel's manuscript was going to press (A. Northedge and D. Kennet, Archaeological Atlas of Samarra, Samarra Studies II, British Institute for Studies of Iraq/Oxbow Books, 2015). But even using that material, the question remains a problem – there are many plans whose functions are not replicated later in Islamic times.

The value of the work lies in its direct address to the subject of Hārūn's residence at Raqqa. It might not have happened otherwise than through a PhD, and the author is to be applauded for that. Caliphal settlements and their organization have not been well evaluated, as few preserve their plans on the surface, and they are too big to excavate more than the palace, e.g. Madīnat al-Zahra’.