The technological developments of the twelfth century, alongside renewed scientific progress, continued throughout the following century. Greater survival of government records confirms that what was happening under the Plantagenets was also to be found under French kings and the Angevin rulers who seized the inheritance of the Hohenstaufen emperors in southern Italy. At a geopolitical level, the entire century was marked by the devastating impact across much of eastern Europe, the Middle East and China of Mongol invasions, and how these nomadic warriors made use of the technology of the people who fell beneath their yoke offers insights into levels of knowledge, as well as the value attached to people who could use it. In military technology, the century witnessed the widespread adoption of the counterweight trebuchet, artillery with revolutionary impact that came to dominate sieges across Europe and the Muslim world. Gunpowder was also first identified in Europe later in this century, although it was already well known in China.

In this chapter I argue that alongside increasingly centralised government there were substantial technological advances (and I examine whether they related to scientific knowledge). Consequent upon both trends, there is evidence of rulers paying more attention to having a body of engineering expertise on which they could call. Greater recognition of the value of engineers and master craftsmen, and (arguably) a greater differentiation among engineers, accompanied these processes.

This was a period in which royal governments in Europe began to become more centralised and more reliant on professional bureaucracies to carry out their functions. This was a slow process and not without interruptions, while in the Holy Roman Empire local princes, bishops and increasingly independent cities themselves consolidated a long-existing de facto right to self-government with only token acknowledgement of the place of the emperor. Frederick II (1212–50), the ultimate failure of whose efforts to assert imperial rights in Italy led to the destruction of his dynasty and the long interregnum that significantly undermined the power and prestige of German emperors, was a man whose wide range of interests included science and technology. One aspect of the process of developing a more bureaucratic and less personal government, the origins of which date back a long way, was the increasing use of paid soldiers to replace armed forces dependent only on feudal levies, with even the aristocracy now expecting reimbursement for service.