Surviving illuminated works attributed to Barthélemy include a Book of Hours (M.358) in the Morgan Library in New York, on which Quarton also worked, and five miniatures added to "The London Hours of René of Anjou" in the British Library which relate very personally and intensely to René's unhappy situation whilst imprisoned in Dijon. Harthan suggests the designs for these may have been sketched by René himself for Barthélemy to execute: "the faithful interpreter of the King's exalted ideas, an inseparable, discreet companion and the effective partner, perhaps, in joint artistic enterprises" [http://www.bl.uk/catalogues/illuminatedmanuscripts/TourPopup.asp?TourID=159].