The monograph provides a comprehensive analysis of the news of the Byzantine emperor Constantine VII Bagryanorodny and other written sources about the origin and resettlement of Croatian tribes, the ethnic history of the Slavic population of the Carpathian region. Taking into account the latest archaeological and linguistic data, issues of the origin of the ethnonym "Croats," the historical conditions of the Slavicization of its original carriers, the Croatian ancestral home are being resolved. The geographical position of Great Croatia, the territorial localization of white Croats, the paths of Croatian migration in the early Middle Ages are established. Designed for historians, teachers and university students, as well as everyone interested in the early history of Slavism.