The millennium between the collapse of the Western Roman Empire in the 5th century ce and the beginning of the colonial expansion of western Europe in the late 15th century has been known traditionally as the Middle Ages, and the first half of this period consists of the five centuries of the Dark Ages. We now know that the period was not as socially stagnant as this title suggests. In the first place, many of the institutions of the later empire survived the collapse and profoundly influenced the formation of the new civilization that developed in western Europe. The Christian church was the outstanding institution of this type, but Roman conceptions of law and administration also continued to exert an influence long after the departure of the legions from the western provinces. Second, and more important, the Teutonic tribes who moved into a large part of western Europe did not come empty-handed, and in some respects their technology was superior to that of the Romans. It has already been observed that they were people of the Iron Age, and although much about the origins of the heavy plow remains obscure these tribes appear to have been the first people with sufficiently strong iron plowshares to undertake the systematic settlement of the forested lowlands of northern and western Europe, the heavy soils of which had frustrated the agricultural techniques of their predecessors.
The invaders came thus as colonizers. They may have been regarded as “barbarians” by the Romanized inhabitants of western Europe who naturally resented their intrusion, and the effect of their invasion was certainly to disrupt trade, industry, and town life. But the newcomers also provided an element of innovation and vitality. About 1000 ce the conditions of comparative political stability necessary for the reestablishment of a vigorous commercial and urban life had been secured by the success of the kingdoms of the region in either absorbing or keeping out the last of the invaders from the East, and thereafter for 500 years the new civilization grew in strength and began to experiment in all aspects of human endeavour. Much of this process involved recovering the knowledge and achievements of the ancient world. The history of medieval technology is thus largely the story of the preservation, recovery, and modification of earlier achievements. But by the end of the period Western civilization had begun to produce some remarkable technological innovations that were to be of the utmost significance. Innovation
The word innovation raises a problem of great importance in the history of technology. Strictly, an innovation is something entirely new, but there is no such thing as an unprecedented technological innovation because it is impossible for an inventor to work in a vacuum and, however ingenious his invention, it must arise out of his own previous experience. The task of distinguishing an element of novelty in an invention remains a problem of patent law down to the present day, but the problem is made relatively easy by the possession of full documentary records covering previous inventions in many countries. For the millennium of the Middle Ages, however, few such records exist, and it is frequently difficult to explain how particular innovations were introduced to western Europe. The problem is especially perplexing because it is known that many inventions of the period had been developed independently and previously in other civilizations, and it is sometimes difficult if not impossible to know whether something is spontaneous innovation or an invention that had been transmitted by some as yet undiscovered route from those who had originated it in other societies.
The problem is important because it generates a conflict of interpretations about the transmission of technology. On the one hand there is the theory of the diffusionists, according to which all innovation has moved westward from the long-established civilizations of the ancient world, with Egypt and Mesopotamia as the two favourite candidates for the ultimate source of the process. On the other hand is the theory of spontaneous innovation, according to which the primary determinant of technological innovation is social need. Scholarship is as yet unable to solve the problem so far as technological advances of the Middle Ages are concerned because much information is missing. But it does seem likely that at least some of the key inventions of the period—the windmill and gunpowder are good examples—were developed spontaneously. It is quite certain, however, that others, such as silk working, were transmitted to the West, and, however original the contribution of Western civilization to technological innovation, there can be no doubt at all that in its early centuries at least it looked to the East for ideas and inspiration. Byzantium
The immediate eastern neighbour of the new civilization of medieval Europe was Byzantium, the surviving bastion of the Roman Empire based in Constantinople (Istanbul), which endured for 1,000 years after the collapse of the western half of the empire. There the literature and traditions of Hellenic civilization were perpetuated, becoming increasingly available to the curiosity and greed of the West through the traders who arrived from Venice and elsewhere. Apart from the influence on Western architectural style of such Byzantine masterpieces as the great domed structure of Hagia Sophia, the technological contribution of Byzantium itself was probably slight, but it served to mediate between the West and other civilizations one or more stages removed, such as the Islamic world, India, and China. Islam
The Islamic world had become a civilization of colossal expansive energy in the 7th century and had imposed a unity of religion and culture on much of southwest Asia and North Africa. From the point of view of technological dissemination, the importance of Islam lay in the Arab assimilation of the scientific and technological achievements of Hellenic civilization, to which it made significant additions, and the whole became available to the West through the Moors in Spain, the Arabs in Sicily and the Holy Land, and through commercial contacts with the Levant and North Africa. India
Islam also provided a transmission belt for some of the technology of East and South Asia, especially that of India and China. The ancient Hindu and Buddhist cultures of the Indian subcontinent had long-established trading connections with the Arab world to the west and came under strong Muslim influence themselves after the Mughal conquest in the 16th century. Indian artisans early acquired an expertise in ironworking and enjoyed a wide reputation for their metal artifacts and textile techniques, but there is little evidence that technical innovation figured prominently in Indian history before the foundation of European trading stations in the 16th century. China
Civilization flourished continuously in China from about 2000 bce, when the first of the historical dynasties emerged. From the beginning it was a civilization that valued technological skill in the form of hydraulic engineering, for its survival depended on controlling the enriching but destructive floods of the Huang He (Yellow River). Other technologies appeared at a remarkably early date, including the casting of iron, the production of porcelain, and the manufacture of brass and paper. As one dynasty followed another, Chinese civilization came under the domination of a bureaucratic elite, the mandarins, who gave continuity and stability to Chinese life but who also became a conservative influence on innovation, resisting the introduction of new techniques unless they provided a clear benefit to the bureaucracy. Such an innovation was the development of the water-powered mechanical clock, which achieved an ingenious and elaborate form in the machine built under the supervision of Su Song in 1088. This was driven by a waterwheel that moved regularly, making one part-revolution as each bucket on its rim was filled in turn.