Khazar Khaganate is the largest and strongest state in Eastern Europe in the 7th-10th centuries. From the middle of the 9th century, Kievan Rus was a tributary of the Kaganate. His possessions extended from the Dnieper and Vyatka to the South Caspian, the rulers of Khazaria competed in their power with the Byzantine Basileus. What kind of state was it? How and who managed to defeat him? The famous writer Mikhail Kazovsky sets out his version of those distant events in the form of an exciting adventure novel. In the center of the plot of the novel is the fate of the wife of Tsar Joseph, the fictional Irma-Irina, an Alanka by birth, expelled by her husband from Itil, sold into slavery to Byzantium, and then participated in the campaign of Svyatoslav and the defeat of the capital of Khazaria - Sarkel.