At different times, and in many regions of the world, religious communities have felt the need to fortify their places of worship. The results are, as might be expected, conditioned by such factors as: the local construction materials and indigenous building traditions; the monetary resources available to the patrons; and the nature of the (real or imagined) external threat. Some monuments were built with their fortifications incorporated into the design, while many others had defensive walls, machicolations, and arrow or gun loops added decades, or even centuries after the initial construction phase. In most cases, these additions were designed to provide shelter in times of emergency or, at least, a feeling of security to an embattled congregation or priest, though this cannot explain all such fortifications. Indeed, the monks of Lindisfarne – subjected to repeated raids by Vikings, Scots, and others since the time of the founding of the mission in 634 – even unsuccessfully lobbied the fourteenth-century king Richard II to have the substantial defences of their church and monastic complex removed (p. 77). Perhaps the inhabitants of this vulnerable island feared the imposition of these royal defences meant a loss of autonomy, and they may even have felt that the presence of fortifications invited rather than deterred future attacks. Whatever the case, it is clear that the motives behind the fortifying of religious buildings were many and varied.

Peter Harrison's book surveys everything from the most monumental structures such as the conventual castles of the Hospitallers and Teutonic knights and the great monastic complexes erected by Buddhist and Orthodox Christian monks to humble parish churches and the rather nightmarish warrens of defensive tunnels and chambers (souterrains) dug beneath churchyards in France. Inevitably, the question of defining what constitutes a fortified religious building presents difficulties. Just as the term ‘castle’ might be applied to a continuum of structures from those which suit our immediate mental template to those that seem to fit more comfortably into other architectural categories, so it proves with the present study. Harrison decides to limit himself “to include only buildings where the religious role had at least equal prominence with any other function, especially the military use, and where, architecturally, the ecclesiastical edifice is subservient to the military” (p. 4). On the same page he notes the basic typological distinctions within the extensive assemblage of buildings surveyed in the book. First, are those unfortified religious buildings that are enclosed within a larger defensive enceinte. The second grouping comprises religious monuments that were themselves equipped with fortifications some time after their initial construction, while his third group is defined, somewhat nebulously, as those buildings that combined elements of both of the former types of fortification.

Although one might have wished for a more fully reasoned discussion of the methodology employed in the selection process and subsequent architectural analysis, there is no denying that the author has identified a significant phenomenon that appears to have been widespread among the Christian communities of Medieval and Early Modern Europe (Chapters 4–10), the Caucasus (Chapter 12), and Ethiopia (Chapter 13), as well as the Crusader states of the Middle East (Chapter 3) and the European colonies of the Americas and the Philippines (Chapter 11). Similar considerations also affected the Buddhist monks of the Himalayas in the construction of their monasteries (Chapter 17), and, to a lesser extent, Muslims in the Iberian Peninsula, North Africa, and the Middle East (Chapters 14–16). The scope of the fieldwork conducted by Harrison is truly impressive ranging across four continents, the author having visited most of the buildings discussed in the book. The author is evidently at ease writing brief, lucid descriptions of the architectural components making up each building, and he gives much useful historical context. While some of the monuments are also served by photographs or visually pleasing line drawings, the book would have been made easier to use had the author included figure and plate numbers in the main text.

Harrison identifies the possible origins of religious fortification in the early history of monasticism in the Middle East (Chapter 1). Although his focus is on the growth of eremetic Christian communities, particularly after the Roman persecutions of the late third century, he also draws interesting comparisons with the ancient settlement of the Essenes at Qumran in Israel. This introductory section leads on to a discussion of fortified Christian architecture in different regions of the world. Since these aspects of the book have been appreciatively reviewed by others, there is little reason to repeat these assessments. Certainly, Harrison builds a persuasive case that this should become a separate category in the history of Medieval and Early Modern Christian architecture.

In the remainder of this review I will consider the arguments advanced to support the contention that Islam also made use of fortifications in religious architecture. Before moving on to these substantive issues, however, some points of detail should be noted. The great early twentieth-century scholar of Islamic architecture is Creswell and not, as stated, Cresswell (pp. 215, 216). I am unclear on what authority Harrison makes the claim that the eighth-century Iraqi palace of Ukhaidir, largely unknown in Europe before the late nineteenth century, “had a profound influence on both Eastern and Western ecclesiastical fortifications” (p. 237). While in chapters 14–16 he writes of the architecture and history of Islam and the Muslims, elsewhere in the book one occasionally finds the author employing the outmoded term, Saracens. Harrison also repeatedly labels Shia groups as ‘heretical’ and ‘fanatic’ though surely these are matters of perspective rather than objective standpoints. More importantly, the author betrays unfamiliarity with the political and religious titulature of the Islamic world in his erroneous employment of the title caliph to refer to the rulers of several Medieval Islamic dynasties. Considerable misunderstanding of basic concepts of Islamic history is also apparent in his claim that the Saljuqs came to power “after they had overcome the Shiite Abbasid dynasty in that part of the Islamic Empire that is present day Iran and Iraq” (p. 239). The reprinting of this book (published first in hardback in 2004) should have been an opportunity to eradicate these, and other mistakes.

In the three chapters devoted to Islamic architecture Harrison seeks to identify building types and specific monuments that conform to his definition of religious fortification. His first example, the ribat, is the most persuasive in that it consisted of a fortified structure located in frontier territory housing garrisons of men (murabitun) who had temporarily forsaken their everyday lives in order to fight the jihad (Chapter 14). Best preserved are the ninth-century complexes at Sousse and Monastir in Tunisia, both of which adopt a plan ultimately derived from the Roman castrum. While such institutions appear from textual sources and toponyms to have been very common across the Medieval Islamic world they have left a rather minimal trace in the architectural record. Their study is further complicated by the likelihood that there was never a standard building form for the ribat.

The second part (Chapter 15) addresses a more diverse group of structures including mosques, citadels, sufi convents (khanqahs), and pilgrimage forts. Allowing for mosques like those of Mahdiyya in Tunisia that are incorporated into town or harbour walls, Harrison's failure to provide primary source material describing places of worship taking on quasi-military roles leads one to question the validity of simply identifying architectural features (such as minarets) that have the appearance of being fortified. At what point also does the presence of religious buildings within a site – Harrison includes the citadels of Cairo and Aleppo and the Ottoman-period city walls of Jerusalem – bring it into the category of religious fortifications? Chapter 16 is devoted to the Ismaili castles of Iran and Syria built between the eleventh and the thirteenth century. Drawing extensively upon the published fieldwork conducted by Peter Willey, Harrison does not provide a sound rationale for the inclusion of these castles into his book. The implicit argument appears to be that the followers of Hasan-i Sabah, and the other charismatic leaders of the Nizari sect were, in their fanaticism, more religiously motivated than the Muslim occupants of other castles in the Islamic world. While this may be the case, it is striking that the author does not devote any attention to specifically religious architecture that must once have stood within these castles. It is unclear how the extensive discussion of the hydraulic engineering in Alamut, for instance, contributes to its status as a religious fortification.

If this general assessment of Harrison's approach to Islamic architecture is rather negative, this does not mean that the questions posed in these chapters are without interest. The intertwining of military and religious concerns is apparent throughout Islamic history. To cite one example, the imposing, fortress-like mausoleum complex erected in fourteenth-century Cairo by sultan al-Nasir Hasan became a refuge for Mamluk factions during times of civil strife. Collaboration between textual historians and students of Islamic architecture could, in future, allow the fortified religious architecture of the Islamic world to be studied in greater depth.