The article presents the results obtained in the course of work on identifying plots in medieval written sources that demonstrate manifestations of the Mongol imperial ideology and allow not only to clearly identify its contours and content, but also to establish with the greatest possible accuracy the moment of transition of the Mongols from predatory and punitive expeditions to systematic subordination of the whole known world space. To achieve this goal, materials contained in the collective work “Collection of Chronicles” (“Jami al-tawarikh”) were analyzed, the compiler and, apparently, the main author of which was a Persian doctor and a major administrator of Jewish origin, Fazlallah Rashid al-Din Hamadani (1247–1318), who served at the court of Ilkhans Gazan (1295–1304) and Oldjeitu (1304–1316). This work is rightfully considered one of the most important sources on the Mongol Empire. In terms of amount of information about its prehistory and early history, it has no equal. The “Collection of Chronicles” contains unique information about spiritual climate of the steppes in XII – early XIII centuries and the personality of Temujin/Genghis Khan (1162?–1227), shedding light on his ideas about the world space and possible plans regarding its subjugation, about conquering plans of his descendants and their implementations. It is difficult to name an aspect of the Mongol imperial ideology that would not be reflected on its pages. Rashid al-Din, as a person who held high positions in the Ilkhanate, had wide access to information, which is why his words, in general, deserve trust and in many cases are confirmed by other sources. Despite the fact that by the time his work was compiled, the Mongol Empire as a whole had not existed for a long time, the “Collection of Chronicles” is permeated with the idea of unity of the Mongol world.