A prime example of a weapon that was used by different Old World cultures at different times is the crossbow. The ancient Greeks were among the first to make use of portable one-man crossbows. This early weapon was called a gastraphetes or "belly weapon" because the user braced the curved centre-piece of the butt end against his chest or belly. Such portable crossbows were never very popular with the Greeks or Romans, and it would have to wait until medieval times for the weapon to gain wide favour in Europe.

The opposite was the case in ancient China, where the crossbow had been the principal missile weapon of Chinese armies since at least the Han Dynasty. Several tombs dating from the 5th and 4th centuries BCE have been found which contained crossbows. The first major improvement in Chinese crossbow design came much later, in the 11th century CE, with the development of the foot stirrup. The stirrup was located at the firing end of the crossbow, just ahead of the bow itself. The user would place one foot in this stirrup while bracing the butt end of the crossbow against his abdomen or chest, thereby giving him greater leverage when drawing the bow. The crossbow’s principal advantage lay in the simplicity of its operation. One aimed and fired it much like a modern handgun. It did not require the years of practice which were necessary in order to master other bows such as the English longbow. By the 13th century, Chinese crossbows were deadly up to 365 metres.

Although crossbows were simple to use, they were complicated to manufacture. Trained craftsmen were needed to manufacture the complex metal trigger mechanisms. Fashioning the bows themselves also required great technical skill, for these were compound bows that were composed of laminated wood, bone, horn, and sinew, melded together for maximum strength and range. The outer convex surface of the bow was reinforced by the animal sinew, while a layer of animal horn or bone reinforced the inner concave surface. The skill needed in making such compound bows had already been developed long before by nomadic peoples of Central Asia such as the Scythians, the Turks, and the Mongols.

Meanwhile, after centuries of relative disuse, the crossbow reappeared in Europe in the 11th century, and it became especially popular in Italy. Strangely enough, the Byzantines did not seem to know about this form of weapon, as a Byzantine chronicler in 1097 referred to the crossbow as a "Frankish novelty." During the Crusades, the Christians learned from the Muslims that compound bows, as used in Central Asia and China, were much more effective than bows made simply from wood alone. The Europeans then improved bow strength still further when around 1370 they began replacing their composite crossbows with steel crossbows. These steel bows had a range of 365 to 410 metres.

But this increased power required a force greater than human muscle power in order to draw the bow. Various mechanical contrivances were devised, such as the "goat’s foot lever" and the windlass – a winch system which drew the bow by means of a double crank. These steel crossbows could now penetrate armour at close range. The Church had been horrified by the power of these weapons, and the Lateran Council of 1139 banned the use of crossbows against Christians, but not necessarily against non-believers. Of course, this restriction was not always strictly observed, and the crossbow would remain a principal item in the arsenals of European armies until their gradual displacement by gunpowder weapons throughout the 14th and 15th centuries.