The Rabbi King: David of Khazaria 1st edition

In history, the Empire of Khazaria occupied southern Russia between the sixth and tenth centuries C. E. In the middle of the eighth century, the Khazar Khagan (king) and nobles adopted Judaism as their religion. The Rabbi King is about a fictional last Khagan of a remnant of Khazaria in the twelfth century. It is the story of David, who is sent to Spain from his homeland in the Caucasus to study Judaism in the same household with a boy later called Maimonides. When the time comes to return home, he leaves civilization to rule an untamed country. It is sparsely populated by pagan nomads and by the descendants of many Jewish immigrants who fled persecution in Persia and Byzantium and intermarried with Khazar converts. David of Khazaria then undertakes a long journey, both physically and spiritually, to save his kingdom from its barbarian conquerors.