From the Encyclopedia Britannica CD 1997 Edition

The appearance of the crossbow as a serious military implement along the northern rim of the western Mediterranean at about the middle of the 9th century marked a growing divergence between the technology of war in Europe and that of the rest of the world. It was the first of a series of technological and tactical developments that culminated in the rise of infantry elites to a position of tactical dominance. This infantry revolution began when the crossbow spread northward into areas that were peripheral to the economic, cultural, and political core of feudal Europe and where the topography was unfavourable for mounted shock action and the land too poor to support an armoured elite. Within this closed military topography, the crossbow soon proved itself the missile weapon par excellence of positional and guerrilla warfare.

The reasons for the crossbow's success were simple: crossbows were capable of killing the most powerful of mounted warriors, yet they were far cheaper than war-horses and armour and were much easier to master than the skills of equestrian combat. Also, it was far easier to learn to fire a crossbow than a long bow of equivalent power. Serious war bows had significant advantages over the crossbow in range, accuracy, and maximum rate of fire, but crossbowmen could be recruited and trained quickly as adults, while a lifetime of constant practice was required to master the Turkish or Mongol composite bow or the English longbow.

The crossbow directly challenged the mounted elite's dominance of the means of armed violence--a point that the lay and ecclesiastical authorities did not miss. In 1139 the second Lateran Council banned the crossbow under penalty of anathema as a weapon "hateful to God and unfit for Christians," and Emperor Conrad III of Germany (reigned 1138-52) forbade its use in his realms. But the crossbow proved useful in the Crusades against the infidel and, once introduced, could not be eradicated in any event. This produced a grudging acceptance among the European mounted elites, and the crossbow underwent a continuous process of technical development toward greater power that ended only in the 16th century, with the replacement of the crossbow by the harquebus and musket.

An independent, reinforcing, and almost simultaneous development was the appearance of the English longbow as the premier missile weapon of western Europe. The signal victory of an outnumbered English army of longbowmen and dismounted men-at-arms over mounted French chivalry supported by mercenary Genoese crossbowmen at Crécy on Aug. 26, 1346, marked the end of massed cavalry charges by European knights for a century and a half (see Figure 6).

Another important and enduring discovery was made by the Swiss. At the Battle of Morgarten in 1315, Swiss eidgenossen, or "oath brothers," learned that an unarmoured man with a seven-foot (200-centimetre) halberd could dispatch an armoured man-at-arms. Displaying striking adaptability, they replaced some of their halberds with the pike, an 18-foot spear with a small, piercing head. No longer outreached by the knight's lance, and displaying far greater cohesion than any knightly army, the Swiss soon showed that they could defeat armoured men-at-arms, mounted or dismounted, given anything like even numbers. With the creation of the pike square tactical formation, the Swiss provided the model for the modern infantry regiment.

As armoured tactics developed, the position of the commander as well as the role he played in battle changed. Primitive and ancient commanders, with the partial exception of Roman ones, normally took an active part in the fighting. They and their medieval successors delivered and received blows themselves as a matter of course, with the result that they were sometimes wounded, as was Alexander the Great, or taken prisoner, as was Francis I of France at Pavia in 1525. However, during the second half of the 16th century bureaucratic means of government began to take over from feudalism, and changing social mores no longer required that rulers fight in person. The switch from hand weapons to firearms itself permitted better control, causing commanders to put more emphasis on directing combat and less on participating in it. Increasingly they were to be found not in the midst of their troops but well to the rear, standing on a hill. After about 1650 they could use a "spying glass," or telescope, in order to distinguish their units (newly clothed in uniform) from one another and from the enemy. To communicate their intentions to subordinates they would rely on messengers--and indeed it was in this period that the modern aide-de-camp made his appearance.

An important 19th-century development consisted of electric communication in the form of the telegraph and, later, the telephone. Replacing mounted messengers with the infinitely faster wire made it possible to exercise active command even with armies very far apart and, equally significant, with armies distant from headquarters, located far to the rear. As a result, distances between field commanders--to say nothing of commanders in chief--and their troops tended to increase until they could be measured in miles and even tens of miles. Commanders and their staffs left the field for the office, getting their information by reading reports and bending over maps rather than peering between their horses' ears. After 1860 the old expression coup d'oeil, which implied a commander "casting a glance" over the battlefield and making his decision on the spot, was replaced by "estimate of the situation," with its connotation of cooler deliberation. The point was reached when, during World War I, commanders from division level up seldom visited the front; nor would the six-foot-deep trenches, screened by concertina in front, have allowed them to take a good look at the enemy even if they had visited it. Moreover, wired communication systems were basically immobile, and efforts to protect them by burying them in the ground tended to make them even more so. In this way they acted as another factor that favoured the defense over the offense.

As commanders came to rely on the wireless communications developed between the world wars, they were able to forsake their headquarters and take to modified tanks, half-tracks, trucks, or even jeeps, which were distinguished from other such vehicles merely by the forest of antennas that they carried. In this way they were able to see the front for themselves and provide leadership at decisive points, all the while keeping in touch with other sectors of the front as well as rear headquarters.

In his memoirs, Dwight D. Eisenhower, supreme commander of the Allied forces during World War II, wrote that soldiers usually welcomed his visits because these meant that there was no danger in sight; but other commanders in that conflict, such as Heinz Guderian, Erwin Rommel, George S. Patton, and even Bernard Montgomery (while still merely an army commander) operated in a very different manner from their World War I predecessors. Instead of ensconcing themselves in châteaus, they roamed all over the theatre of war, not seldom taking to the air and covering hundreds of miles in a single day.

Regarded from this point of view, radio helped to reverse a secular trend that had been unfolding for centuries, enabling those who knew how to use it to bring about a revolution in command. But for this, modern armoured operations as pioneered in World War II would have been impossible.