Military discipline has always been an essential element in maintaining order and efficiency in the armed forces. Unlike modern regulations, medieval military law was less formalised, and disciplinary sanctions often depended on the ruler or commander. Nevertheless, certain rules and mechanisms were put in place to regulate the behaviour of combatants. Medieval military discipline was based on a combination of feudal traditions, chivalric codes, royal law and ecclesiastical authority. Punishments were harsh and direct, designed to maintain order in situations where chaos and lack of discipline could determine the outcome of a battle or an entire campaign. Discipline was often imposed arbitrarily, and the authority of the commander, ruler or master of the order was crucial in enforcing the law.
In this article, the author attempts to trace the main legal aspects of military discipline; the ordinances in England and in France proved to be the most important. In both kingdoms, they played a great role during the Hundred Years’ War (1337–1453), when the need to reform both the French and English armies was crucial for survival, for success on the battlefield, and for maintaining the internal stability of the army. They also became an important element in the professionalisation of the armies, which were evolving from feudal forces into more permanent and controlled military structures. Military ordinances helped to maintain discipline, reduce chaos during campaigns, and ensure better treatment of civilians and prisoners of war.