"Essays on the History of Byzantium and the South Slavs" was written by order of the State Educational and Pedagogical Publishing House of the Ministry of Education of the RSFSR in 1958 as a textbook on the medieval history of the Balkan Peninsula and Asia Minor. Until the departure of A.P. Cajan to the United States in 1978, the book was on the list of educational literature of the history department of Moscow State University.