This book tells how the Arabs lived before the advent of Islam, how Muhammad first preached in Mecca and how the Muslim community - the Ummah - arose in Medina, how the Meccans and Medinas argued for power after the death of the founder of Islam, how it was formed and began its the conquest of the Arab Caliphate and how this state expanded, including all new territories - the Arabian Peninsula, Iraq, Iran, Transcaucasia, Central Asia, Syria, Palestine, Egypt, North Africa, the Pyrenees. And also about how the conquered countries were governed, how riots were suppressed, how cities developed, how Arab culture gradually matured, how relations between the Caliphate and Byzantium were built, and much more. A fundamental work on the early history of Islam and the Arab Caliphate by Evgeny Belyaev is published in a new edition. Evgeny Belyaev (1895–1964) - Arabist, Doctor of Historical Sciences, headed the department of history of the countries of the Near and Middle East at the Moscow Institute of Oriental Studies, was a researcher at the Institute of Oriental Studies of the USSR Academy of Sciences .