The article uses materials of Byzantine historical works of the XIII-XIV centuries to further develop the author’s work in the sphere of Imperial ideology of the medieval Mongols. The special geopolitical position of Byzantium, as well as controversies among descendants of Genghis Khan, have caused peculiarities of its relations with the Mongol Empire, and later with the states of Juchids and Khulaguids, and allowed it to remain independent. Byzantine historians described the Mongols from the position of external observers, so their information is relatively scarce, but important for understanding the goals of the Mongol conquerors in the region and their views on the world order. Analysis of information provided by George Pachymeres, Nicephorus Gregoras, and other Byzantine intellectuals suggests that the Mongol leaders demonstrated considerable flexibility in their foreign policy and did not show any claims to world domination. The sources also reproduce a number of stories concerning the Mongols, which are also known from the Christian historiography of the South Caucasus and the Middle East, in particular, they speak out the idea of nomads who invaded the cultural lands as a “scourge of God”, but they are still far from an eschatological interpretation of the Mongol invasion and do not interpret it in terms of “the whole world”. They do not express thoughts about the need to submit to this inevitable evil. Byzantine authors describe quite accurately the goals of Mongol conquest campaigns and diplomatic activities of the Mongol leaders. It can be assumed that relations between Byzantium and the Mongol states were built on an equal basis, or the Byzantine authors carefully avoided any hints of inequality in their works. The image of Genghis Khan drawn in the analyzed sources does not contain anything messianic or heroic; moreover, not all authors know who exactly was a founder of the Mongol Empire, and they attribute the leadership of Genghis Khan’s military campaigns to his descendants. Thus, the Mongol “imperialism” in the Byzantine sources is very poorly traced, which, however, does not detract from their value in reconstruction of the mental climate of the Mongol Empire and its historical successors.