This book presents the results of ‘The Hagia Sophia’ project, which ran from 2004–2018, focusing on the immediate surroundings of the sixth-century church as well as its fourth- and fifth-century predecessors. The church building is considered as part of an agglomerate of numerous auxiliary structures, the roles of which in understanding Hagia Sophia have been considerably underestimated. Over the course of the project, the researchers were given access to previously unseen features of the original sixth-century structures. In addition, access was granted to decorative elements, including mosaics and frescos, revealed by the removal of plaster and sometimes whole modern structures disguising the original arrangement. This book contains a wealth of useful and previously unpublished archaeological information that has never been available to scholars before. As such, it is the first comprehensive reassessment of the original sixth-century building complex of Hagia Sophia written in decades, and offers some valuable new insights into the functional organisation of the various architectural spaces, in particular the episcopal complex to the south-west of the church itself.

The structure of the book follows the basic chronological developments of the Hagia Sophia compound. Chapter 2 carefully re-examines the literary and archaeological evidence of elements related to the first two ecclesiastical buildings, followed by a discussion of the sixth-century church in Chapter 3, and post-Justinianic modifications in Chapter 4. The fifth, and final, chapter is dedicated to the sixth-century church in its broader context, re-evaluating the cultural and religious significance of Hagia Sophia as part of Justinian's wider building campaign; this remodelled the entire monumental centre of Constantinople in an effort to provide an urban context for a new Christian identity and imperial legitimacy.

Hagia Sophia is arguably the best-known and most intensely studied Byzantine church, and Dark and Kostenec combine evidence from former studies with new findings to provide the latest publication in a long sequence of scholarly work. While previous research often considered the church in isolation, the main theme of the present volume is the significance of associated structures for both the layout of the church and its function. In Chapter 2, for instance, the authors advance novel interpretations of the functional purpose of the hypogeum and skeuophylakion to the north of the church, emphasising that the location of burials may have been significant in Hagia Sophia's fourth- and fifth-century incarnations. Before the end of the fifth century, it is argued, Constantinople may have essentially been a Roman city, only subsequently transformed into a distinctly Christian place.

In addition to the well-known sixth-century features of Hagia Sophia, the authors propose that the vestibules at all four corners of the edifice, as well as the remains of the patriarchal palace to the south-west, are also of Justinianic date. Chapter 3 offers a reconstruction of the original sixth-century configuration of various subsidiary structures such as the buttress piers, access ramps, vestibules and patriarchal palace, based on detailed architectural surveys of the masonry—some of which is newly exposed. In the discussion of the small octagonal building to the south of the main church, commonly identified as a baptistery, and the remains of some massive piers to the north of Hagia Sophia, the authors present an interesting idea. Whereas the octagon may in fact have initially been built as a reception room belonging to the patriarchal palace, a large rectilinear structure built over the hypogeum to the north might have been the Great Baptistery mentioned in written sources. Similarly, new archaeological evidence appears to confirm sixth-century descriptions of courtyards paved and clad in white Proconnesian marble surrounding the Great Church.

In Chapter 4, the various architectural structures examined in earlier chapters are revisited in respect to post-Justinianic modifications and in light of the changing liturgical roles of the individual spaces. Particular attention is paid to the corridor of St Nicholas, which, according to the textual evidence, connected the two eastern vestibules, and the renovations and additions to the patriarchal palace that apparently was not substantially rebuilt after the sixth century. Parallels with archaeologically identified episcopal palaces in other parts of the Byzantine Empire (e.g. Anatolia, Cyprus, Balkans, Greece) are used in the final chapter to establish architectural and conceptual similarities in their design and function. The book culminates in the contextualisation of Hagia Sophia within the monumental centre of Constantinople in the early Byzantine period that is seen as an expression of both quintessentially imperial Roman, and Christian, identity.

The archaeological evidence connected with the dating and attribution of architectural and decorative elements in the immediate environs of Hagia Sophia represents a valuable contribution to the study of the monument and a rich source of information for future research. It is not made clear, however, why these new findings necessitate a complete “revision of recent studies of the geometry, architectural design, lighting, stability and spatial organisation of the building” (p. 128). While the auxiliary structures certainly influence the way in which the ecclesiastical complex relates to the wider urban context and how the building is accessed and movement directed, these structures do not change the conceptual design and layout of the church building proper.

The book assumes that readers are on intimate terms with the site and, consequently, descriptions of minor architectural elements are sometimes difficult to follow. Numerous detailed ground plans are provided, but the authors do not refer to the numbers identifying individual features in the plans in their discussion. Although richly endowed with black-and-white in-text photographs, these do not always offer the necessary clarity. Generally, the book would have benefited from a more systematic presentation of the material evidence independent of its interpretation. In the same vein, a thematic rather than a chronological structure may have provided a more constructive framework, thus avoiding repetition and frequent cross-referencing. The value of the book undoubtedly lies in the publication of new archaeological material made available by rescue and development activities conducted by the museum authorities.