ENThe article is devoted to a comparative analysis of the historical ideas of Russians and Belarusians about the Grand Duchy of Lithuania. The author comes to the conclusion that the historical views of the neighboring peoples were of a dual nature. In Russian historical culture, the Grand Duchy of Lithuania acted as one of the centers of gathering Russian lands, and, at the same time, was steadily associated with a foreign invasion from the West. The Belarusians began to form Belarusian identity within the principality, however, a spiritual split took place, and the border of civilizational confrontation did not pass between peoples, but between the nobility and the lower classes. Therefore, folk versions of history, not burdened with the accuracy of the chronicles and the imagery of Sarmatian ideology, largely reflected an alternative view, in which social sympathies and antipathies were refracted in a peculiar way. The article presents a mosaic of images and stable epithets associated with the historical conditions of the coexistence of Russians and Belarusians within the border states. The medieval worldview of the two peoples, who had a common ancient Russian and Orthodox heritage, and opposition to paganism, and subsequently to the Catholicism of Lithuania, brought them closer together. In Russian texts, the author revealed the reflection of dynastic and military-political ties between the Lithuanian and Russian states, the events of the Russian-Lithuanian wars, sympathy for individual allied Lithuanian princes, the consequences of the «Lithuanian ruin» and some characteristics of «cultural heroes» attributed to «Lithuania».In the Belarusian historical culture, the expanded image of the Grand Duchy of Lithuania is found only in the written culture of the nobility, who found themselves in the orbit of another civilization and gradually lost their spiritual connection with their people, as well as among the urban population, who defended their status rights. The analysis of the texts made it possible to establish that the glorification of wars and princes is not characteristic of the folk ideas of the Belarusian peasants, historical details are not required, but the experiences of ordinary people, who were exposed to devastating invasions, captivity, and forced separation from their families, are important. Therefore, the content of the Belarusian ballads is largely identical to the Russian songs about the Tatar area. Attempts to «reconstruct» the Belarusian heroic epic in the spirit of fantasy chivalry, based on national mythological falsifications, have little in common with genuine works of folk art. Some Belarusian legends about Prince Vitovt either «ground» his origin, fit him into the expectations of the people’s ruler, or endow him with the role of a «cultural hero» transforming the local landscape. The latter finds analogies in Russian toponymic legends, however, on the other side of the border, the image of Vitovt the enemy, who personified the «Lithuanian ruin», was more important. Key words: folk historical representations, Russians, Belarusians, the Grand Duchy of Lithuania, ethnic consciousness, folk memory, epos, traditions, legends, toponymy, historical culture, medieval consciousness. [From the publication]