Elley and Omogoy are considered the legendary ancestors of the Sakha (Yakuts), the indigenous people of North-Eastern Siberia. We have put forward a hypothesis that the legendary Elley is a historical person and the first pastoralists in the territory of the middle Lena. The aim of the study search for Elley historical prototype and determine the probable time of his arrival in the middle Lena and the origins of cattle breeding in this territory. Subjects and methods. The analysis of all the existing versions of the legends about Elley, data from humanitarian, historical, archaeological, genetic studies, which have a connection with the historical prototype of the hero. Results. Analyzing the Sakha legends about the ancestors, we concluded that the personalities and events described in these legends are based on real historical facts. Probably, cattle began to breed on the territory of Yakutia during the rise of the Xiongnu at the beginning of our century. Conclusion. A number of scientific facts indicate an earlier period of the appearance of the Yakut cattle breed in Yakutia. At the present time, we can state with a certain degree of probability that the personality of Elley is connected with the events that took place in the XII century in East Asia during the period of Song China.