Non-biblical sources of the treatise «On the preaching of the Holy Cross against Saracens» by Humbert of Romans. Part 1

The article represents a survey of the results of the work on identification of the non-biblical sources of the Humbert of Romans’ treatise «On the preaching of the Holy Cross against Saracens» and general analysis of the use of these sources. The full version of the results will be published in the critical edition of the text. The article is divided into three parts. The first part deals with the sources of the Late Roman Empire and Early Middle Ages used in the treatise.