The paper deals with the matter investigating the nature of the aesthetic impact of the belles-lettres style being generated within the scope of great transfer from high Middle Ages to the start of Renaissance. In course of the analysis, some traditional ideas and terms adopted in the historical stylistics are used. The mentioned ideas turned up into being during the period of its discrimination from other disciplines of linguistic historical cycle. Acquired linguistic independence charged the ideas with the function of marking the borders between the historical stylistics and other disciplines mentioned. One of the markers of the type is the voluminous historism, i.e., co-relationship between stylistic phenomena and the context of their existing. Flexible borders of the latter regulated by targets and tasks of the proper research can be extended up to the certain type of culture. Importance of a special character gained by the medieval culture during the period of the international Gothic dominating when considered as a type of a context necessary for analysing the belles-lettres style generating corresponds to the importance of combining philological and non-philological kinds of practice and induced by the purpose to enrich the analysis as well as to increase the research output verification. It is suggested that the analysis of the elements of another semiotic nature presented by types and illustrations highly important for discursive strategies to influence the recipient should be thought of as an instance of a combination of the kind. One of the mighty instruments of the mentioned sort of the esthetic impact is the medieval illuminated book of the epoch of the international Gothic (XIV - XV centuries) dominating within the borders of European cultural space. Soft power, immanent to it, id est, some ability to modify emotional state of consciousness and behaviour of a recipient is characterised by semiotic attractionness and cognitive power, and embodies one of the type of strategies of the kind.