In China for most of this period the guiding text remained Sun Tzu's Art of War, dating to the 4th century B.C.E., along with associated commentaries by later writers. In 1571 the Ming author Qi Jiguang published a treatise on strategy and tactics called Lianbing shiji, in which he proposed major reforms that included mixed fighting brigades and a new emphasis on firearms, along with a special corps of war wagoneers and portable defensive walls for field armies. In Europe the most widely read and venerated medieval text was Epitoma de re militari, a study of the late Roman Army in the West written by Vegetius in the late 4th (or possibly, the early 5th) century. It was available initially only in Latin, but later was translated into most of the major vernacular languages.
Vegetius stressed the inherent tactical superiority of defense in war, recommending fortification but also close-order infantry formations to enliven this principle. This emphasis on a ''Fabian strategy'' of defense and attrition was well-received in an era that found offensive war too difficult, expensive, and unrewarding: medieval commanders husbanded armies out of fear of the high stakes of battle, in preference for siege warfare, or to conduct chevauche´es. Other medieval military lore and literature included rules and histories of the Military Orders, especially the Templars; tales, fables, and some serious memoirs of the Crusades; and contemporary chronicles, notably that by Froissart during the Hundred Years' War (1337-1453). During the Italian Renaissance new attention was paid to histories and biographies of classical military leaders, primarily Alexander the Great, Julius Caesar, Quintus Fabius Maximus, Sulla, Scipio Africanus and other notable Roman generals, and Hannibal of Carthage.
In the early 1490s Leonardo da Vinci published Codex Madrid II, a highly influential and reliable guide to gun types and gunpowder recipes. At the start of the 16th century Niccolo' Machiavelli wrote his Art of War (''Arte della guerra'') urging revival of Graeco-Roman virtues and citizen military systems, reflecting on the respective merits of militia versus mercenaries in his own day, and arguing for a strategy of annihilation of enemy armies as the path out of indecisive yet ruinous condottieri wars. Although Machiavelli did not transform Florentine military capabilities as he hoped and has received sharp criticism from modern military historians, his work was quite influential on developments in the Netherlands a century later where it inspired Justus Lipsius to write De Militia Romana (1596). In turn, that helped shape neoclassical military reforms introduced by Maurits of Nassau. The key contribution made by Machiavelli and Lipsius was renewed emphasis on military discipline and drill. In the view of Max Weber, this led to a shift in military norms that initiated the final transformation to true gunpowder armies: ''gunpowder and all the war techniques associated with it became significant only with the existence of discipline.''
Professionalism and social acceptance of military careers as suitable for the middle classes took hold by necessity and in advanced imaginations during the 16th-17th centuries. Printing presses and expanded lay literacy led to a proliferation of new military manuals and texts. Most had some practical utility and reflected the new cultural empiricism, even though many merely relied on reworkings of classical texts and formal ideas. Niccolo' Tartaglia published his extraordinary study of ballistics, Nuova Scientia, in 1537. In France, Marin du Bellay's Discipline Militaire appeared in 1548, while John Smythe published Instructions, Observations, and Orders Mylitarie in England in 1598. On the new style and techniques (alla moderna) in fortification, J. Perret published Des fortifications et artifices d'architecture et perspective in 1594; a Dutch military engineer, Simon Stevin, published De Sterctenbouwing in 1594.
The real impact of military literature came with illustration of the new tactics and drill methods introduced by the Dutch. In 1607, Count Johann of Nassau, brother of Maurits, published the first fully illustrated drill manual under the nom de plume ''Jacob de Gheyn.'' His Exercise of Arms for Calivres, Muskettes, and Pikes (the English translation) was widely copied, amended, and reprinted in multiple languages. His sponsorship of a military academy in Siegen (''Schola Militaris''), to educate better officers in the service of Dutch Reform in arms, led to wide dissemination of Dutch ideas and drill techniques. Its director, Johann Jacob von Wallhausen, published numerous training manuals. Lesser authors still found it necessary to pretend to a classical pedigree in order to gain wide acceptance.
Thus, in 1616, John Bingham, an English officer who had served with the Dutch, published The Tacktics of Aelien, purporting to study classical principles of war but really reporting on the Dutch system. More self-consciously empirical and up-to-date was Robert Barret's 1598 tract Theorike and Practike of Moderne Warres. Other influential works included Nicholas Goldman's La nouvelle fortification, published in Leiden in 1630. As a result of the English Civil Wars (1639-1651) a host of manuals and works in English appeared, including how-to books by artillerymen and other veterans such as John Vernon's Young Horseman, or Honest Plain-dealing Cavalier, published in 1644. Others were solid memoirs published decades later by experienced field commanders such as George Monk.
