For all the potency of the English longbow from the mid-fourteenth century, the crossbow had a longer-term influence on medieval warfare and may well have been the principal stimulus behind the emergence of the great helm and the development of plate armour in the thirteenth century. It had been known and widely used from the mid-eleventh century. During the thirteenth century the improved, composite crossbow spread throughout Europe; thereafter it was the most important missile weapon in many parts of Christendom. Although not a fast-shooting weapon, and perhaps more suited to siege warfare than the battlefield, it was powerful and versatile, and was also less dependent than the longbow on physical strength and lengthy training. Mail offered little protection against crossbow bolts (quarrels) and given that the steel crossbows of the fifteenth century could have a draw weight of 1,000 lbs (the string being pulled by means of a windlass), it is likely that the crossbow maintained its position as a penetrative weapon against plate armour rather more successfully than the longbow.
The thirteenth century witnessed a gradual rise in the importance of light infantry. As the crusaders returned from the Levant to western European battlefields, they brought with them a new appreciation for the effectiveness of light infantry, an appreciation that would raise the position of archers and crossbowmen on the battlefield, but in varying degrees. In England, Anglo-Norman border wars against the Welsh and Scots produced a profound respect for the range and power of the longbow, while on the continent, well grounded in chivalry and feudalism, Italian crossbowmen mercenaries would be utilized as a subordinate arm to French and German noble heavy cavalry.
Light infantry archers and crossbowmen were not uncommon in western European warfare before the thirteenth century. Light infantry was easily conscripted because the bow was a peasant weapon used for hunting (and poaching), and the crossbow was a point-and-shoot mechanical device that took a short time to master, an ideal characteristic for use by city dwellers. But the high Middle Ages was the plateau of chivalry, a time when the mounted nobleman lancer ruled the courts and battlefields of western Europe. In this social climate, weapons systems of the common man, no matter how effective, were looked down upon in a contempt born of fear. So powerful was this fear that the medieval period’s most powerful institution, the Catholic Church, passed legislation at the Second Ecumenical Lateran Council in 1139 anathematizing all who used the crossbow and bow in wars between Christians (later, the killing of infidels with missile weapons was acceptable). In many ways the Catholic Church was bowing to the demands of a noble class who feared death by arrows and bolts from a distant, anonymous killer.
The basic construction of the crossbow was a small bow attached to a stock that provided a groove for the bolt. The bowstring was held in place when cocked by a simple trigger mechanism. Early crossbows used a wooden bow, and the string could either be drawn by hand or with the aid of a simple claw or goat’s foot. But by the thirteenth century the crossbow had evolved with the addition of a composite bow made of horn, sinew and glue. The composite crossbow required a stronger cocking mechanism, a problem solved with the invention of the windlass. The windlass used pulleys attached at the butt end of the stock to a winding mechanism which, when hooked onto the bowstring and wound, would draw the string to the trigger. By the fifteenth century the bow of the crossbow was made entirely of metal, increasing its power, range and ballistic impact. With a maximum range of almost 500 yards and the ability to pierce the best plate armour, the metal crossbow became the most dangerous non-gunpowder missile weapon in use by medieval light infantry.
Although medieval commanders recognized the importance of combined arms in winning on the battlefield, commanders differed in how they respected and employed light infantry. On the continent, crossbowmen were often favoured over archers because of the small amount of skill required to operate their weapon. The French crown regularly employed Italian mercenaries renowned for their skill with the crossbow. In England, King Edward I (r. 1272–1307) first conquered the Welsh, then assimilated their native weapon, the longbow, into his army, creating a very dangerous weapon system for use against the Scots and later, by his successors, against the French.
Good as the longbow was, the crossbow had its merits, too. The Saracens called the crossbow qaws Ferengi (“Frankish bow”) because the Crusaders used it with such great success against Arab and Turkish horsemen. A crossbow had a short, very powerful bow (known as a prod), made of wood or steel and mounted on a wooden stock made of yew, ash, hazel, or elm.38 Crossbow bolts were much shorter than arrows. Unlike a longbow, which was extremely difficult to draw and which could not be held at full draw for more than a second or two seconds, a crossbow was cocked by means of a mechanical device (a lever or a crank on a ratchet) and did not require a great deal of strength to operate.
It was thus an ideal weapon for a young soldier or even for a boy (it required much less upper body strength than a longbow) or for an exhausted adult soldier. Moreover, thanks to its trigger mechanism, it could also be kept cocked for a long period of time with no effort on the part of the crossbowman. This permitted more accurate aiming when it was ﬁnally time to shoot: there were two or three notches on the stock in which to rest the thumb, which could then be lined up with the crossbow bolt to form a rudimentary sight. Early wood crossbows in the Middle Ages had an effective range of about 350 yards; the later powerful steel crossbows were more accurate, had a ﬂatter trajectory, and a longer maximum range (of up to 500 yards).
On the battleﬁeld, a crossbowman was very vulnerable when reloading his weapon—a slow and complicated process. He therefore protected himself by ducking behind a broad, four-to-ﬁve-foot-high convex shield known as a pavise, which when marching he carried slung across his back. Before a battle began, he propped up the pavise in front of him so that it would stay put. A pavise could also be used as part of a defensive screen called a pavisade, which was formed by setting up a row of pavises side-by-side. In this whole process, the medieval crossbowman was often assisted by one or more helpers.
Crossbows could not be ﬁred as rapidly as longbows (their rate of ﬁre was only about two crossbow bolts per minute) but they released more kinetic energy. Most of these crossbow bolts could penetrate mail; sometimes, with a solid hit at close range, they could even kill a knight in full armor. Moreover, a raw recruit could be taught how to use a crossbow in only one week, whereas combat competency with a longbow required many years of constant practice. The ability to use the crossbow was widespread. For example, all Venetians learned how to ﬁre one as part of their civic obligations, and it was the usual weapon of garrison troops and town guards.
Anna Comnena (1083–1153), a remarkable Greek aristocrat who was the daughter of Emperor Alexios I Komnenos of Byzantium (and also, in her own right, a scholar, a doctor, and a hospital administrator) gives us, in her book the Alexiad, a description of a very powerful crossbow. It was, she says, a fearsome new weapon:
The crossbow is a weapon of the barbarians, absolutely unknown to the Greeks. In order to stretch it one does not pull the string with the right hand while pushing the bow with the left away from the body; this instrument of war, which ﬁres weapons an enormous distance, has to be stretched by laying almost on one’s back; each foot is pressed forcibly against the half-circles of the bow and the two hands tug at the bow, pulling it back with all one’s strength toward the body…. Along [a groove in the stock of the crossbow] arrows of all kinds are ﬁred. They are very short but extremely thick with a heavy iron tip. In the ﬁring the string exerts tremendous violence and force, so that the missiles wherever they strike do not rebound; in fact, they transﬁx a shield, cut through a heavy iron breastplate and resume their ﬂight on the far side…. Such is the crossbow, a truly diabolical machine.
Although in the 12th century the crossbow almost completely replaced the longbow in most European armies, this was not the case in England. The English preferred their tried and true longbows. Under King Edward I’s sponsorship, Welsh and English archers perfected, through long arduous years of frequent practice, the strength, technique and discipline required to draw the longbow to the ear and then send storms of accurately-aimed arrows into advancing cavalry and infantry formations. Indeed, during the battle of Crécy in 1346, English archers may have ﬁred as many as half a million arrows during the course of this ﬁght. Arrow wounds made horses unmanageable, thus deﬂecting a cavalry charge; ranks of lightly-protected foot soldiers could easily be decimated.
In the armies of Europe, mounted and unmounted crossbowmen, often supported by archers and javeliners, were assigned to a central position in battle formations. Mounted knights armed with lances were ineffective against formations of pikemen who were combined with crossbowmen, whose weapons could penetrate the armor of many knights. As better mechanisms for cocking crossbows were developed, they could also be used on horseback, leading to new cavalry tactics. Knights and mercenaries were deployed in triangular formations, with the most heavily armored knights in the forefront, some of them carrying small but very powerful all-metal crossbows.
It is interesting to note that crossbows are still said to be used today by commando forces in Serbia, Greece, Turkey, and Spain. Chinese armed forces use crossbows at all unit levels, from traffic police to the elite Snow Leopard Commandos of the Chinese army. One reason for this is the crossbow’s ability to stop persons carrying explosives without the risk of causing detonation. Another is that they kill silently and at a distance—a combination which may be an asset for authorities if they are trying to break up a terrorist or criminal attack.
The rank of commanding officer of the crossbowmen was one of the highest positions in a medieval army. In most European armies, mounted and unmounted crossbowmen, together with archers and javeliners (a javelin was a light spear thrown by hand), were assigned to a central position in battle formations. The crossbowmen would open ﬁre on enemy forces before an attack by the crossbowmen’s forces of mounted knights. Crossbows were also used in counterattacks to protect one’s own infantry.
The arbalest was a later and much more powerful version of the crossbow. It had a steel prod, i.e., a steel bow; was bigger and heavier than earlier crossbows; and, thanks to the greater tensile strength of steel, it delivered far greater force. A large, windlass-cocked arbalest could have up to 5,000 pounds of power and could be accurate (against a very big target, such as a fortification) at more than 900 yards. Arbalests were sometimes considered to be inhumane and unfair weapons because they allowed a lightly-trained commoner to kill, safely and at relatively long range, a noble knight who had perfected his own ﬁghting skills over the course of a lifetime of tournaments and battles.