It took several decades for gunpowder weapons to come into use everywhere in Christian Europe and the Muslim world, but once they were acquired there was never any chance of going back. Despite the considerable limitations of early guns, no ruler (king, sultan, prince or prince bishop, doge or city corporation) failed to take up this new technology. For most of the fourteenth century, major constraints were imposed by limitations in metalworking skills and unsolved problems in the combining of the ingredients and the process of making the powder itself. By the end of the century, both issues were largely resolved, allowing the creation of new generations of weapons during the following century that changed the face of warfare. Even before this point the manufacture of gunpowder and of guns had become a major industry, but the role of master gunner had yet to achieve the importance that would be attached to it as the weapons themselves began the journey towards becoming decisive from the middle of the fifteenth century.

For most of the fourteenth century more traditional technology continued to be dominant and the engineering skills called upon by commanders during the previous century continued to be as valued as those of people making and operating the new weapons. In western Europe, the decision of the English king Edward III (1327–77) to reassert his claim to rule France led to the intermittent but seemingly interminable conflict now known as the Hundred Years War, generating regular bloody warfare (albeit usually with impact limited in time and place) from Iberia to Scotland. In the Baltic, the theocracy established by the Teutonic Knights, ejected like their fellow crusading orders from the Holy Land in 1291, ignited conflict with the pagan inhabitants of Prussia and Lithuania and, eventually, with neighbouring Christian states. In Asia Minor the dynasty founded by Osman in the early fourteenth century ultimately came to dominate the Muslim world as the Ottoman empire, on the way completing the destruction of Byzantium, briefly interrupted by the invasions of Timur, latest (and last) of the great Mongol conquerors, who marched undefeated across central Asia, India and Asia Minor at the end of the fourteenth century.