A complete illuminated manuscript in 52 full page color plates Bérault Stuart, seigneur d'Aubigny (c. 1452-1508) was a French soldier and diplomat who belonged to the notable Scottish family the Stewarts of Darnley. Over a distinguished career he served as chamberlain and royal counselor to the King of France and held various military and diplomatic positions in service of the monarchy. In 1508, shortly before his death, he dictated the Traité Sur l'Art de la Guerre (Treatise on the Art of War) to his chaplain. The treatise is a practical discourse on warfare and statecraft, drawing on contemporary works and his own military experience. The present manuscript, held by the Beinecke Rare Book and Manuscript Library, Yale University, is one of a small number of surviving manuscripts of the work.