The book of the outstanding Russian Byzantinist Alexander Petrovich Kazhdan (1922-1997) gives a comprehensive picture of the life of the Byzantine Empire of the 10th-12th centuries. It was a period of economic and cultural prosperity, a time when basically what constituted the essence of Byzantinism was formed. The reader will get an idea of ​ ​ the diverse internal ties in the life of Byzantium, get acquainted with its various aspects, ranging from natural and material conditions to aesthetic views and theological disputes. The work combines rigorous scholarship with intelligibility and clarity of presentation. It will be read with enthusiasm not only by specialists, but also by everyone who is interested in the problems of Byzantine history and culture.