The information on this page has been borrowed from Medieval Warfare. Please support the official release.
The medieval knight was usually mounted and armoured, often connected with nobility or royalty, although especially in north-eastern Europe knights could also come from the lower classes.
The cost of a knight's armour, horses, and weapons was great. This helped transform the knight, at least in western Europe, into a distinct social class separate from other warriors.
During the crusades, holy orders of monks who were also knights were created, including the Knights Templar, the Knights Hospitaller and the Teutonic Knights. They were formed to fight in the Holy Land and became the "storm troops" of the Christian crusaders.
Heavy cavalry, armed with lances and an assortment of hand weapons, played a significant part in the battles of the Middle Ages. The heavy cavalry consisted of nobles and wealthy knights who could afford the equipment.
Heavy cavalry made the difference between victory and defeat in many key battles. Their charges could break the lines of most infantry formations, making them a valuable asset to all medieval armies, the equivalent of twentieth century tank regiments.
Light cavalry consisted of lighter armed and armoured men, who could have lances, javelins or missile weapons, such as bows or crossbows. Light cavalry were used as scouts, skirmishers or outflankers. Many countries developed their own styles of light cavalry, such as Hungarian mounted archers, Spanish jinetes, Italian and German mounted crossbowmen.
Crusaders tended to favour heavy cavalry mounted on mares while the Saracens favoured light cavalry mounted on stallions.
Infantry were recruited and trained in a wide variety of manners in different regions of Europe all through the Middle Ages, and probably always formed the most numerous part of a medieval field army. Many infantrymen in prolonged wars would be mercenaries. Most armies contained significant numbers of spearmen, archers and other unmounted soldiers.
In sieges, perhaps the most common element of medieval warfare, infantry units served as garrison troops and archers, among other positions. Towards the end of the Middle Ages, with the advancements of weapons and armour, infantrymen became more important.
In the earliest Middle Ages it was the obligation of every noble to respond to the call to battle from his liege lord with his own equipment, archers, and infantry. This decentralized system was necessary due to the social order of the time, but could lead to motley forces with variable training, equipment and abilities. The more resources the noble had access to, the better his troops would typically be.
Typically feudal armies consisted of a core of highly skilled knights and their household troops, mercenaries hired for the time of the campaign and feudal levies fulfilling their feudal obligations, who usually were little more than rabble. They could, however, be efficient in disadvantageous terrain. Towns and cities could also field militias.
As central governments grew in power, a return to the citizen and mercenary armies of the classical period also began, as central levies of the peasantry began to be the central recruiting tool. It is often claimed that the best infantrymen came from the younger sons of free land-owning yeomen, such as the English archers and Swiss pikemen.
England was one of the most centralized states in the Middle Ages, and the armies that fought the Hundred Years' War were mostly paid professionals. In theory, every Englishman had an obligation to serve for forty days. Forty days (called quarantine) was not long enough for a campaign, especially one on the continent.
Scutage was introduced, under which most Englishmen paid to escape their service and this money was used to create a permanent army. Almost all high medieval armies in Europe were composed of a great deal of paid core troops, and there was a large mercenary market in Europe from the early twelfth century.
As the Middle Ages progressed, both the Papacy and Italian cities began to rely mostly on mercenaries to do their fighting rather than the militias that had dominated the early and high medieval period in this region. These would be groups of career soldiers who would be paid a set rate. Mercenaries tended to be effective soldiers, especially in combination with standing forces. In Italy they came to dominate the armies of the city states. While at war they were considerably more reliable than a standing army, but in peacetime they proved a risk to the state itself (as the Pretorian Guard had once been in Roman times).
Mercenary-on-mercenary warfare in Italy led to relatively bloodless campaigns which relied as much on manoeuvre as on battles, since the condottieri recognized it was more efficient to attack the enemy's ability to wage war rather than his battle forces,, and attempting to attack the enemy supply lines, his economy and his ability to wage war rather than risking an open battle, and manoeuvre him in a position where risking a battle would have been suicidal.
Knights were drawn to battle by feudal and social obligation, but also by the prospect of profit and advancement. Those who performed well stood to increase their landholdings and advance in the social hierarchy - this was a major factor in the Crusades in the Holy Land and also European crusades such as the Albigensian Crusade - the War against the Cathars of the Languedoc.
For the mounted knight Medieval Warfare could be a relatively low risk affair. Nobles avoided killing each other, rather preferring capturing them alive, for several reasons for one, many were related to each other, had fought alongside one another, and they were all members of the same elite culture; for another, a noble's ransom could be very high, and indeed some made a living by capturing and ransoming nobles in battle.
Huge ransoms could be demanded for captured knights and more still for high nobles and kings. Some knights made their fortunes by fighting. William the Marshall being the best known example. Even peasants, who did not share the bonds of kinship and culture, would often avoid killing a nobleman, valuing the high ransom that a live capture could bring, as well as the valuable horse, armour and equipment that came with him. On the other hand it was quite common, even at the height of "chivalric" warfare, for the knights to suffer heavy casualties during battles. Christendom was shaken when King Peter II of Aragon was killed fighting on the side of his vassal Raymond of Toulouse at Muret in the Languedoc.
Clergymen played a major part in battles - from their planning to building siege engines (a clerical specialty), encouraging the troops and taking part in the fighting. We have many accounts of senior clergy leading battles and not only during the crusades. They are also depicted in contemporary art - popes, cardinals and bishops, wearing full armour and wielding weapons. The role of military bishops is commemorated today by the presence of four bishops on a chess board. Clerical combatants are depicted in medieval art and according to tradition favoured the mace as a weapon (a mace could kill without shedding blood which the Church considered desirable).
On the other hand swords feature more heavily than maces in the arms of England bishops Knights Templar and Knights Hospitaller, the shock troops of Christian armies, were monks in the fullest sense- they took the same vows as other monks in addition to their vows as knights. If caught by the enemy they were almost always executed while other knights were usually ransomed. The reason was that they were such fanatical fighters that it made sense to put them permanently out of the war whenever possible.
The practice of carrying relics into battle is a feature that distinguishes medieval warfare from its predecessors or from early modern warfare. The presence of relics was believed to be an important source of supernatural power that served both as a spiritual weapon and a form of defence; the relics of martyrs were considered by Saint John Chrysostom much more powerful than "walls, trenches, weapons and hosts of soldiers" - another reason for so many lost battles.
In Italy, the carroccio or carro della guerra, the "war wagon" , was an elaboration of this practice that developed during the 13th century. A Carroccio was a four-wheeled war altar drawn by oxen, used by the medieval republics of Italy. It was a rectangular platform on which the standard of the city and an altar were erected. Priests held services on the altar before the battle, and the trumpeters beside them encouraged the fighters to the fray.
The carro della guerra of Milan was draped in scarlet cloth and drawn by three yoke of oxen caparisoned in white with the red cross of Saint George, the city's patron, it carried a crucifix so massive it took four men to step it in place, like a ship's mast.