In his Dialogue, probably written between 1419 and 1421, Thomas Hoccleve cites one of the most important military manuals circulating in the Middle Ages: Vegetius' De re militari. On the one hand, this reference simply serves as a compliment to Humphrey, duke of Gloucester's martial prowess: Humphrey is such a good military commander that he can afford to ignore perhaps the most influential military handbook of his time. Hoccleve presents De re militari as an educative, didactic text; one that can teach ‘the art of chiualrie’ to those less well ‘preeued’ in the art of war than Humphrey. Yet, Hoccleve's representation of De re militari as a text which would have been translated were it not for Humphrey's martial skill points, perhaps unconsciously, to an alternative situation that would necessitate the translation and reading of Vegetius: a context in which there was a lack of military ‘maistrie’, an insufficiency in, or ignorance of, the art of war. Such ignorance might even lead to military defeat, the proof of which would lie, not in the citation of the conquest of Cherbourg ‘among othre’ towns, but in a catalogue of failed sieges and lost territories.