The book consistently examines the activities of the first four, the so-called "righteous" caliphs who came to power after the death of the founder of the Islamic religion, Muhammad, as well as the rulers of the Umayyad dynasty who replaced them. The author focuses on such issues as the socio-economic state of the Caliphate in the 7th-8th centuries, the struggle of the ruling dynasty with its political opponents, the state and administrative structure of the Caliphate in the period under study.