The third and final book of the trilogy about our contemporary, who, by the will of fate, found himself on a planet very similar to his home world. Having successfully adapted to Byzantium, and then moved to the lands of future Rus', the earthling, together with his associates, created his own early medieval power. Having successfully repelled the aggression of the Normans and the Khazar Kaganate, using his knowledge and pursuing a far-sighted policy, he is establishing the state on a new basis - trying to change the fate of the East Slavic peoples. (Book 3 “Demiurge of History” is a continuation of the stories “Avatar from the Earth” and “Rodomysl”) .P.S. Some characters in Chapter I are partially taken from the story “Rosichi” by the Ukrainian writer Valery Chmyr.