The growing fascination of researchers with early modern cultural brokers and go–betweens has increasingly connected historical area studies with European and global history. Recent studies on converts between Christianity and Islam (by Tijana Krstić and Marc Baer, among others) have opened up the field and provided insights into a fascinating topic for Ottomanists as well as Europeanists. Tobias Graf's book, a revised version of his doctoral thesis from the University of Heidelberg, offers a new look at the biographies and transcultural links of early modern Christians who turned Muslim and became subjects of the Ottoman sultan while often retaining certain connections to their former homelands. His study focuses on the decades surrounding the so-called Long Turkish War, namely the years between 1580 and 1610. Whereas documents from the Ottoman side, according to the author, usually remain silent on the Christian pasts of these renegades (p. 2, passim), the book relies mainly on sources from Central European archives and libraries, such as travelogues, scattered private letters and diplomatic correspondence. The author manages to identify 137 individuals of a Central European or Italian background who switched allegiances and ‘defected’ to the Ottoman sultan for a variety of reasons. Using a mix of quantitative analysis and micro-historical approaches, Graf traces their lives, family ties and political as well as social affiliations between Christian Europe and the Ottoman realm. Special emphasis is laid upon the role of these converts within Ottoman society and also on their remaining links to their former homelands.

The first chapter following the introduction contains a lengthy discussion of the term ‘renegade’. It continues with a depiction of the various ways in which converts became integrated into the Ottoman military and administrative elites. In line with current research, the author discusses typical features of sixteenth-century Ottoman society such as the devşirme system (the levy of Christian boys for service in the army and state) as well as the significance of household structures and meritocracy. Chapter ii, ‘Turning Turk’, analyses the symbolic and bodily practices of conversion, such as a change of clothes, circumcision and modes of enslavement. It becomes clear that conversion was more than just a change of faith: for an individual, it rather meant an ‘extensive cultural transformation’, while contemporaries saw it mainly as a ‘change of loyalties’ (pp. 87–8).

The third part is dedicated to the possible motives of converts and the circumstances of conversion. It discusses a number of different options that range from religious indifference and/or a fascination with Islam to hopes of material success. In some cases, contemporaries considered seemingly deviant practices such as regular drunkenness or homosexual inclinations as decisive for a change of sides. However, what mattered from an Ottoman point of view was, according to Graf, not the convert's past but loyalty to the sultan and state. Contrary to conversions to or within Christianity, a ritual embrace of Islam was not the end of a longer process but rather the beginning of a period of indoctrination and spiritual learning (p. 111).

Chapter iv looks at the post-conversion careers of the renegades in the Ottoman Empire, including several fascinating social advancements to the highest ranks of the state. Sometimes converts used their knowledge and particular language skills to act in intelligence and espionage. Often their personal networks were based on shared geographical origins (p. 149). Converts were instrumental in establishing trans-imperial links especially in the Ottoman border zones or the newly-conquered territories of south-eastern Europe. Moreover, it becomes evident that renegades did not break completely with their former lives and social relations. This fact is also illustrated in chapter v, which deals with the maintenance of family ties and home contacts among converts, making use of famous examples from an Italian context (the Cigala family, among others). Family reunions and money transfers between a renegade and his family hint, according to the author, at a general ‘cosmopolitanism of European elites, including that of the Ottoman Empire’ (p. 184; see also the conclusion at p. 207). This chapter thus not only puts the Ottomans on the map of a cosmopolitan Mediterranean in the decades around 1600, but it also underlines in particular the contemporary usefulness of the otherwise-derided renegades in social, political, military and economic respects.

The study illuminates the relationship between conflicting religious truths and state formation through the lens of individual converts and their careers. While the spiritual aspects of a conversion do not feature prominently in the book, the stories presented by Graf are often as much about conversion as about geographical mobility between the Christian and Ottoman-Muslim worlds. Such mobility appears as a highly common phenomenon of the later sixteenth century. Wherever archival documentation allows, the book provides a mix of case studies and more structural approaches. Many of the biographies, stories and sources presented here are not unknown to either Ottomanists or Europeanists, but the study certainly benefits from connecting and contextualising them. The author is well-informed in the social and cultural history of the Ottoman empire, although it feels that due to the scarcity of material on his protagonists, a broader contextualisation sometimes takes too much space and serves as filling material. Regarding the overall phenomenon of Christian-Muslim converts in the decades around 1600, Graf's sample of 137 individuals can certainly be only the tip of an iceberg. At times however, even this impressive sample seems too small and problematic for quantitative analysis (cf. p. 71). Occasionally, the lack of better archival documentation makes room for speculations on the author's part that sometimes leave the reader not fully satisfied.

These critical remarks aside, the book nevertheless provides fascinating insights into the culture of conversion and an early modern Christian–Islamic cosmopolitanism. Graf's depictions of the renegades’ careers lead the reader into a world of inter-religious exchanges that is certainly not easy to trace in today's archives, even though the phenomenon was quite common for contemporaries four hundred years ago.