International audienceThis article reports on the research that has been carried out collectively since 2006 on manuscript 1 of the Public Library of Semur-en-Auxois, dating from around the year 1000, comprising the hagio-liturgical dossier of Saint John of Reome and a series of later additions. It exposes the structure and contents of the main and oldest core of the manuscript, insisting on the singular testimony that it bears on the three translations of the body of the saint. Finally, it proposes the transcription of the late medieval lists that were associated with it, and which were still largely unpublished.Cet article fait état des recherches qui ont été réalisées collectivement depuis 2006 sur le manuscrit 1 de la Bibliothèque munic...