The book of the French historian Ferdinand Chalandon (1875-1921) is dedicated to the period of the reign of Emperor Alexei I Komnin (1081-1118), the first emperor from the Komnin dynasty. Based on large factual material, this work is still the only consolidated work on the initial period of the Komnins' reign, and already, therefore, deserves attention. As the founder of the new dynasty, Alexei I gave Byzantine politics the direction that it maintained throughout the 12th century. His reign ushered in a new era in the history of East-West relations. The direct merit of F. Chalandon is the development of the actual history of Byzantine politics in Asia Minor and the reconstruction of the chronology of the entire period of the reign of Alexei I. Based on the analysis of all the information available to the scientist, he recreated the dating of the wars of this emperor with the Italian Normans, with the Pechenegs and Polovtsy on the Balkan Peninsula, with the Iconian Sultanate and individual emirates of the Seljuk Turks in Asia Minor. The book also scrupulously analyzes the foreign policy of the Byzantine Empire, in particular, reconstructs the chronology of the relationship between Alexei Komnin and the leaders of the First Crusade