The book by a famous Russian researcher gives a detailed description of Byzantine and Arab societies during the era of the rise of Islam, showing the history of military-political relations between Byzantium and the Arab Caliphate in the 7th–8th centuries. and mutual cultural influences until the 11th century. The book is written on the basis of medieval Greek (Theophanes, Nikephoros, etc.), Arabic (Balazuri, Tabari, etc.), Armenian (Sebeos, Ghevond, etc.), Latin and Syriac sources, used partly in the originals, partly in translations. For wide range of readers. The publishing layout is saved in a4.pdf format.