To say it in advance: this book was long overdue. It is the first modern scientific monograph to do justice to the history of the County of Tripoli in the twelfth century apart from Jean Richard's concise Le comté de Tripoli sous la dynastie toulousaine (1102–1187) from 1945. A remarkable strength of the book is that the author has used and thoroughly evaluated sources in Western languages as well as the works of Arab chroniclers. Since they have named Count Raymond IV of Saint-Gilles and his successors as Counts of Tripoli Sanjīl and ibn Sanjīl respectively, Lewis has also deliberately chosen the name Sons of Saint-Gilles as a subtitle. At the same time, he aims to show with his work “that the counts of Tripoli were westerners in name and self-perception, yet worked within a distinctly Syro-Lebanese framework” (p. 7).

The book is based upon Lewis’ doctoral thesis of 2014, which was more thematically structured. It was not only revised for publication, but the whole structure was changed ‒ perhaps to fit into the series “Rulers of the Latin East”. A first glance at the table of contents gives the impression that it is a purely chronological presentation of the history of the Counts of Tripoli in the twelfth century with a focus on the history of events. Fortunately, this is not the case, for the book is not limited to a thorough description of the political and military events and contexts, which is based on an excellent knowledge of the sources. On closer reading, one can certainly see that the topics addressed in the original title of the dissertation “Rule and identity in a diverse Mediterranean society” – now, however, more or less hidden in the text and therefore not always easy to find – are certainly addressed and thoroughly discussed.

Contrary to what Jean Richard states, Lewis points out that the population of the County of Tripoli was far too heterogeneous in terms of ethnicity and religious affiliation to be perceived as explicitly “Provençal” by Arab authors. While the king of Jerusalem felt like the “King of the Latins” since 1115, and Hans Eberhard Meyer speaks of the “Latin Christian Staatsvolk” (p. 90), according to Lewis the Count of Tripoli never felt himself to be “count of the Provençales” – rather “the county itself [was] not exclusively or homogeneously Occitan” (p. 91). Only in the capital Tripoli did the Occitan element predominate. Unlike the Kingdom of Jerusalem, where, according to Ronny Ellenblum, the Franks lived and interacted more frequently with the native Christian population in the historically sedentary regions than with the Muslims in the traditional nomadic areas, according to Lewis, the geographical conditions in the county were the deciding factors: Lebanon and its offshoots determined with which groups of locals more intensive contacts took place. But where Latins and local Christians lived side by side, their contact was not limited to the economic sector. Besides, Lewis notes that the opinion once voiced by Prawer about Jerusalem that the Latin people had avoided rural areas for settlement and preferred to live under the protection of towns and fortresses, which is now refuted by archaeological studies, does not apply to the county either. Lewis also points out that Latins and local Christians living together was by no means always characterized by peaceful coexistence, but sometimes by mutual mistrust or even hostility. To illustrate this, he describes an episode from 1137, when Bazwāj, the Muslim ruler of Damascus, invaded the county. Count Pons, who went to meet him, suffered a severe defeat and was killed. Lewis vividly describes how his son and successor Count Raymond II took revenge for his father's death. Blaming local Christians for the murder, Count Raymond II invaded villages of the Nestorians and Jacobites and brought the survivors – Christian men, women, and children – to Tripoli, where they were publicly tortured to death.

On the other hand, he was not afraid to enter a purposeful alliance with the Muslims. After the failed crusade of 1148, when his cousin Bertrand of Toulouse took the fortress ʿUrayma north-east of Tripoli, Raymond did not want to accept it and thus ultimately caused a huge scandal by asking Nur al-Dīn, the Muslim prince of Mosul, for help. Nūr al-Dīn seized the fortress and kidnapped Bertrand, who was taken into Muslim capacity for ten years. Both events revealed Raymond II the military weakness of his county. Count Pons had already called the knights of the Hospital of St John into the country to assist in the fight against enemies and had generously provided them with land. Raymond II followed his father's example and asked the Templars for help. Although the county was protected from the Muslims in the medium term, it increasingly fell into the hands of the military orders.

Although all this and much more can be read clearly, even excitingly, in this impressive book, its structure is not always user-friendly. The table of contents is almost meaningless, and the subchapters do not occur in the text; the index is likewise insufficient. The aspects of social, economic and administrative history, which are unfortunately treated somewhat briefly, are not dealt with in subchapters but are integrated throughout the book and cannot be found via the index. So the reader has difficulty finding them and is more or less forced to read the book from the first to the last page to get a comprehensive overview. Also, the book incomprehensibly lacks a final summary. The conclusions at the end of each major chapter are hardly a substitute for this.

But despite these criticisms, the book is an important contribution to the history of the Crusades and the Latin East as a whole and a benchmark in the history of the County of Tripoli in particular, due to its impressive wealth of material and its many new insights.