Medieval society thoroughly encouraged young males of social standing to seek glory in war. They were provided with role models both in fiction—as in the Arthurian legends or the French “chansons de geste”—and in tales of the feats of contemporary real-life heroes such as England’s Black Prince or Bertrand du Guesclin, the constable of France. The Church sanctified the practice of war, at least if directed against “infidels” or in some other just cause, and the code of chivalry established principles of conduct that a knight should follow.
Chivalry incorporated many of the usual principles of warrior morality, such as loyalty to your leader or to your brothers-in-arms, together with Christian-derived values such as respect for the poor and needy. But the chivalric code was also a practical arrangement between knights to limit the risks of warfare. Being of the same rank and often related by blood or marriage, opposing knights had an interest in avoiding a fight to the death. If they were facing defeat, they could usually surrender in the confident expectation of being treated well as prisoners and eventually ransomed—although there were exceptions to this rule, as when the English King Henry V ordered the killing of French prisoners at Agincourt in 1415.
Ransoms could be considerable sums of money, so there was obviously a profit motive at work in the preservation of prisoners’ lives. However much knights might be inspired by the prospect of honor and glory, they usually also had material goals in sight. Many knights were far from wealthy. They might hold fiefs that were small plots of land similar to those worked by peasant families, or they could be younger sons with no expectation of an inheritance. Skill in the use of arms gave a man a chance to better himself. He could forge a distinguished military career, as Bertrand du Guesclin did from unpromising provincial origins, or win lands through participating in conquest, as happened during the Crusades.
Kings increasingly assumed the exclusive right to confer knighthoods and used this as a means of raising revenue, charging a hefty fee for the privilege. By the 14th century, many qualified by birth to be knights tried to avoid the expense and onerous duties it involved. As well as the cost of the accolade, there was a substantial outlay for equipment and mounts. A knight needed at least two horses when on campaign—a palfrey, or saddle horse, for ordinary travel and a splendid destrier, or warhorse, for combat. Full plate armor, which gradually replaced the mix of chainmail and plate, was very expensive, shaped to offer protection against missiles and sword blows, yet light and well balanced enough to be comfortable when fighting on foot. The knight would also need a lance, a sword, a shield, and probably a mace, war-hammer, or poleax.
Many young men with military ambitions were prepared to pay for the horses and gear but baulked at the cost of a knighthood, or lacked the requisite birth qualification. They remained squires or sergeants, fighting alongside the knights and largely indistinguishable from them on the battlefield. A squire or sergeant might hope to receive an accolade on the battlefield in recognition of some spectacular feat of arms, though such on-the-spot knightings were not common. Knights, squires, and sergeants were collectively known as “men-at-arms”.
Knights broadly fitted into the system of personal loyalty and mutual obligation that shaped medieval society. They might, for example, owe military service as vassals or liegemen to a lord or king in return for a grant of land held as a fief—the classic pattern of the “feudal” system. But in the later Middle Ages monetary arrangements progressively came to the fore. Whether knights lived on their own land or as retainers in a noble household, by the 14th century they would expect to be paid for their services, even though the service was recognized as a feudal obligation. By the same token, they could often pay money in lieu of service—shield tax or “scutage.”
Knights were not always so lofty in their pretensions. Others became outright mercenaries, leading “free companies” that were in effect private professional armies, selling their services to cities and states, none of which could afford to maintain permanent standing armies. Thus the force that a medieval king led off to war would be far from homogenous. It might include his own household knights, his barons or lords and their feudal followers, contingents provided by the military orders, and mercenaries led by their own chiefs. At worst, during times of disorder and social breakdown, knights might degenerate into brigands, using their skills to carve out a dishonest living through robbery, plunder, and pillage.
Well-made armor offered excellent protection and gave a knight full mobility to wield his lance, sword, or ax, in the saddle or out of it. The shock of close-quarters combat was, of course, intense and put a premium upon physical strength and endurance, especially if hot weather made the weight of the armor hard to bear. But fortified by their code of personal honor and duty, knights rarely flinched once combat was joined. Their chief weakness lay in the intemperate aggression and quarrelsomeness of hot-headed individuals bent upon glory. Chronicles of medieval warfare tell time and again of groups of knights unwisely breaking ranks to charge a superior enemy in a self-conscious show of competitive bravery, often in defiance of a battle plan agreed in advance. The knights’ discipline rarely matched their valor.
Even in the 14th century, the battlefield dominance of knights was challenged by lightly armored foot soldiers at Courtrai and Bannockburn and by archers at Crécy. From the second half of the 15th century, gunpowder weapons were increasingly effective, as were disciplined infantry armed with pikes. But armored cavalry was not driven from the battlefield by arrows, cannon or arquebuses. In something close to its medieval form it remained an important element in battles into the late 16th century. By then, however, the social and cultural basis of knighthood had declined with an increase in central state power and the inexorable rise of professional soldiering.