After a series of studies dedicated to the relations between Turks and Byzantium published in various journals or collections of studies, Rustam Shukurov provides in this book a comprehensive and impressive image of something which could be considered, as Barbara Tuchman has wrote for the western fourteenth century, a "distant mirror." This mirror shows to us how a well-organized and administered empire, reduced in size after the Fourth Crusade, confronted an immigration process that eventually contributed to its destruction ("how the encounter with the alien Turkic culture affected Byzantine civilization and what the specific features of the Turkic invasion were that made the Turks victorious") (1). The author defines this encounter as a conflict of civilizations, where the Turkic factor influenced both from outside and from inside, the result being the transformation of the Byzantine society and culture. Shukurov follows the path opened by the classical work of S. Vryonis , including also the European possessions of the empire (he also emphasizes that the two areas, western and eastern, should be studied in comparison each to other where it concerns the Turkic immigration, and that another comparison, between northern and Anatolian Turks, is imperative for this study).
The first major contribution of this monograph (chapter 1) is the explanation for why Byzantine authors applied archaic names to contemporary populations. Due to the Aristotelian paradigm, the Byzantine mentality was not able to classify the species of a genus other than as a bipartition. For the Turks, who belonged to the larger genus of barbarians, there were two generic classes available according to their homeland (because the geographical position was the recognized criterion): northern (therefore, Scythai, or sometimes Ounnoi and Tourkoi) and eastern (therefore, Persai). Across the world known by them, the Byzantines located peoples according to the division in seven climates inherited from the classical geography, a theory which also was supposed to explain the definitory features of their inhabitants. These large categories were in their turn divided according to the place in several subspecies with names derived or not from the main category (for instance Massagetai, Persoskytai, Persotourkoi). Only some of the subspecies render the real names of the ethnic groups (Patzinakoi, Koumanoi, Mougoulioi). All ethnic names were dependent on the geographical position and the ethnicity described by common language being considered important ("Byzantines did not develop language typology, as we do today, and did not look for genetic links between different languages. Similarly, they did not problematize the learning and knowledge of foreign languages, which remained on the utilitarian level of everyday life," 52-53). For the name Persai, the assimilation of the Persian culture by those Turks who settled in Anatolia also mattered.
As it is shown in the beginning of the second chapter, the method used by Shukurov to study the Turkic people established in the Byzantine Empire was the building of a database filled with information gathered from every available kind of sources, from narrative writings to monastic documents or lead seals. The use of Arabic, Persian, Turkish or Slavonic writings was very important in addition to those by the Byzantines or Western. The database resulted in a sum of 350 names of Oriental origin for the European part, and one of 65 for Anatolia. The entries were classified with the following fields: 1-Family name or sobriquet; 2-Etymological interpretation; 3-Baptismal name; 4-Occupation and social status; 5-Location; 6-Floruit; 7-Family links; 8-Primary sources; 9-Secondary sources (65-68). The best-known area is Macedonia, due to the nature of the sources (many names were recorded in monastic documents). The investigation establishes genealogic relations when possible. The person names were divided in "two groups among the owners of Oriental names, if their origin was not specified in sources: the Qipchaq Turks and Tatars, that is, 'Scythians,' and Anatolian immigrants, that is, 'Persians.' The main criterion for my division is the locative characteristics of the name's owner (or of his ancestors) and not the linguistic features of name. The proposed division into 'Scythians' and 'Persians,' being absolutely transparent to the Byzantines themselves and acceptable to us, has nothing to do with modern linguistic systematization" (85).
In the third chapter two generic Turkic groups who entered the empire, "Persians" or "Scythians," are studied. Be it noble or common people, mercenaries, civilians or slaves, they were an increasingly presence. While previous studies concerned mainly the Turkic mercenaries, this book attempts a "comprehensive and generalizing study on the place of the Turks in the ethnic composition of Late Byzantium." The author's goal is to find "whether they constituted compact ethnic groups, where they lived, or what their religious and cultural affiliations were" (90). In the western part of the empire, the Cumans were already present from the 11th century, but new groups settled until the beginning of the fourteenth century. In Anatolia, the sedentarization of the Turkic nomads progressed at the same time as the settlement of Seljuq mercenaries in the empire. A crucial event was the new migration of 1262 stirred by the Mongol expansion. Is the well-known group led by sultan ʿIzz al-Dīn Kaykāwus II (1237-1280), about whom Shukurov has already written a preliminary study.  The issues discussed include the chronology of the settlement, the involvement of the sultan in international relations (Byzantium, Mamluqs, Bulgaria), the members of his family, the migration of the nomadic Turks in the empire together with the sedentary Seljuqs. A still controversial problem is the settlement in today Dobrudja of a group of such nomads led by a Sari Saltiq. According to many historians, their offspring are the so-called Gagauzi, who now are living in the southern parts of the Republic of Moldova.  It is regrettable that Shukurov did not express his point of view on this problem.
Discussing the settlement of a Turkic emir Malik in Morea in 1263, Shukurov considers that the land called Vlachia in the Chronicle of Morea where this Malik settled is Dobrudja (121, 125). It is true that Dobrudja was then inhabited by a mixture of population which included Romanians (Vlachs), but the Vlachs had there no political organization of their own, the region being a part of the Bulgarian state. As I already observed in my recent book, all the references to Vlachia in the Chronicle of Morea concern a land in Thessaly, mentioned with this name in several sources. 
The rest of the third chapter enumerates the many involvements of Nordic and Anatolian Turks in the Byzantine political and military history, and their continuous settlement as military or landowners, thus opening the detailed discussion on the Turkic presence of the Byzantine Turks in the Balkans, a topic dealt with in the fourth chapter. Using the previously mentioned database and the toponymy, the author defined the settlement areas in Macedonia for the Cumans (mostly in west and north) and for the Anatolian Turks (in south). The migration started in Anatolia in 1262 had great effects. They came mostly as military, and then remained as permanently inhabitants, still Muslims, or more and more converted to Christianity and mixed with locals.
In the fifth chapter, Shukurov made full use of his database to reconstruct genealogies of several noble families of Turkic origin assimilated in the empire, even up to the eleventh generation for Melik. This prosopographical part of the book is of great importance for understanding the process of integration of upper class immigrants. They were mostly from the Anatolian stock.
The ways in which integration or assimilation were made possible are discussed in the sixth chapter. Like the late antique barbarians, the Turks were attracted by the refined way of life offered by the empire. Christianization was the main tool to achieve integration, and sometimes it was followed by the granting of pronoiar properties to immigrant soldiers. In fact, the majority of the immigrants were a part of the military entered in the service of the Byzantine army, even in high positions or in the administration ranks. In some cases, these troops had their own Turkic commander. Other Turks are encountered among slaves or prisoners. The increasing presence of Turks in the Byzantine population was not perceived by the Byzantines as the constitution of an ethnic minority in our terms, since they legally were too Romaioi. What mattered was the belonging to the Orthodox faith, not the ethnic origin.
Turkic presence in the Pontic empire of Trebizond, using a variety of Oriental sources left until now outside research by the Byzantinists, is studied in the seventh chapter. This state was in close relationships with the Ilkhanate, most probably based on a tribute payment (Mongols were attested among the settlers in this state, besides the Turks). The alliance defended the Trebizond state against the Turkic nomads, but this functioned only until 1330 when began a large wave of migration. On the whole, this state was much more opened to Turkic immigration, as testified by the marriage policy of the dynasty, and to a lesser extent by the mercenaries in comparison with the Nicaean/Constantinopolitan Empire.
The linguistic and civilizational consequences of the contacts with the Turkic populations are discussed in the eighth chapter. The influences at the lexical level were mostly linked with the new things introduced by means of these contacts, in the spheres of clothing, household items, food, medication, or concerning some species of animals. Another category concerns the superior level of the commercial and military terminology. It should be emphasized that many Turkic or Persian words assimilated in the medieval Greek language were afterwards borrowed in the South-Eastern languages, such as Bulgarian and Romanian, and are still in use but sometimes with changed meanings.  The many examples enumerated in this chapter and in the subsequent glossary (chapter 9) are of great interest for the study of the Byzantine civilization. Inside the Byzantine world, the contacts with the Turks developed the mental horizon, for instance by adopting foreign geographical and ethnographic terminology (one such case is the name of the Black Sea, originally a Turkic one). The result was the coexistence of genuine Greek and Oriental borrowings in different fields, from trade or buildings to food. The final consequence was bilinguism, well attested in the first half of the fifteenth century for the entire Byzantine state, and, as the author says, "The latent Turkification of Byzantine society," defined as "the significant penetration into the Byzantine environment of Turkic ethnic elements that transformed Late Byzantine mentality. This mental transformation consisted of a gradual adoption of the realities of the alien Turkic world as an equal (or almost equal) version of Byzantium's own world" (380). This was the ultimate result of contact between a Christian Byzantine society and the Turks, and one of the reasons for the collapse of the empire.
In his concluding remarks, Shukurov describes the different impact of the Turkic presence in Macedonia in comparison with the Trapezuntine Empire ("Asian immigrants in the Pontos were generally more numerous and more successful socially, while lower- and middle-class immigrants in Macedonia probably had to struggle to disguise their Asian ancestry") (416). Regarding the conversion to Orthodoxy, this was not complete in the Trapezuntine state, with some Muslims preserving secretly their original faith. At the end of this remarkable book, Shukurov concludes that the latent Turkification did not result in what we call now a multicultural society. This process which "undermined Byzantine self-identity and modified traditional Byzantine mental patterns" explains why the fall of the Greek empires was prepared by three centuries of increasing Oriental influence (419).
1. S. Vryonis, The Decline of Medieval Hellenism in Asia Minor and the Process of Islamization from the Eleventh through the Fifteenth Century (Berkeley, 1971).
2. R. Shukurov, "Sultan ʿIzz al-Dīn Kaykāwus II in Byzantium (1262-1264/1265)," in Der Doppeladler. Byzanz und die Seldschuken in Anatolien vom späten 11. bis zum 13. Jahrhundert, eds. Von N. Asutay-Effenberger, F. Daim; Byzanz zwischen Orient und Okzident, 1 (Mainz, 2014), 39-52.
3. With the exception of G. Atanasov, Dobrudžanskoto despotstvo. Kăm političeskata, tsărkovnata, stopanskata i kulturnata istorija na Dobrudža prez XIV vek (The Despotic Domain of Dobroudja: About the Political, Clerical, Economical and Cultural History of Dobroudja in the Fourteenth Century) (Veliko Tărnovo, 2010), 401-439, who tried to demonstrate that the Cuman origin is the only explanation for their Christian faith.
4. A. Madgearu, The Asanids: The Political and Military History of the Second Bulgarian Empire (1185-1280); East Central and Eastern Europe in the Middle Ages, 450-1450, 41 (Leiden, 2016), 157, 254.
5. For influence on Romanian language and civilization, see L. Şăineanu, Influenţa orientală asupra limbei şi culturei române, vols. 1-2 (Bucharest, 1900); F. H. Wendt, Die türkischen Elemente im Rumänischen, Berliner Byzantinische Arbeiten, 12 (Berlin, 1960).