In Europe, the windmill was one of the greatest scientific triumphs of the medieval age. Though the technology spread throughout Europe in the Middle Ages, it was especially important in northern and western Europe, particularly England, Scandinavia, Holland, Belgium, France and Spain. The earliest verifiable reference to a European windmill comes from a late twelfth century manuscript, while other evidence reveals the presence of windmills elsewhere in Europe in the thirteenth century. These European windmills differed from the earlier Persian model in their orientation—the Persian windmills rested on a horizontal plane, while the European models stood tall on a vertical plane. The earliest windmills in Europe appear to have been post mills, whose central body rested on a series of posts and could be rotated to match the changing direction of the wind. These were increasingly replaced in the fourteenth century and beyond by tower mills. Unlike the post mill, which rotated its entire body to meet the wind, the
blade mechanism of the tower mill was positioned at the top. The top could rotate to adjust to wind direction, but the main frame of the mill stayed in place. This allowed for the construction of sturdier frames, built out of brick or stone rather than wood. Stronger towers could support heavier and larger rotary blade mechanisms, which in turn allowed tower mills to capture more of the wind’s energy than post mills. Tower mills, however, were more expensive to build, and as such, both tower and post mill technology continued to be used throughout the Middle Ages.
Windmills were built to serve a variety of functions, such as raising water for irrigation or sawing wood. By far the most important function of windmills, however, was to grind grain for food. In this period, a typical western European family would consume about 1.2 bushels of wheat and barley per week. Grinding this amount of grain by hand was extremely time consuming, requiring about nine hours of labour.