This book presents the results obtained from the historical and archaeological investigations carried out in the framework of a project centred on the site of Shayzar, in Central Syria: Shayzar Project: study of the fortified settlement in Bilad al-Sham. On the basis of a detailed analysis of the archaeological evidence, and of the study of the written documentation available, the book examines the origins and the development of this fortification, especially in relation to the most crucial period as regard as the building of the citadel, i.e., the span of time that stretches from the 10th to the 13th centuries; it also discusses the development of building techniques in the context of military architecture.