This article aims to evoke a military treatise entitled Epitoma Rei Militaris, written between 383 and 450 d.C. by a high imperial official called P. Flavius Vegetius [or Vegetus] Renatus. But more than to remember the main contents of this work, its internal organization, its sources or its objectives, this paper analyzes the reception of the Treaty of Vegetius throughout the Middle Ages and seeks to explain why this work has become one of the most copied, most translated and most quoted books in Europe until the early Renaissance. Keywords: Roman army, Vegetius, Military Treatises, Warfare in the Ancient World, Medieval culture.