The problem mills solved
Most medieval people ate bread, porridge or other foods made from grain, and grain has to be ground. For thousands of years this was done by hand with stones, a slow and tiring job that often fell to women in the household. Animals could turn a larger millstone, but they needed feed. Moving water and moving air were free, so using them to turn a wheel was a sensible way to save labor.
The watermill was not a medieval invention. Roman writers described it, and it existed in the late ancient world. What changed in the Middle Ages was how widely it spread, how many different jobs it was adapted for, and how much it became a regular part of the landscape.
Watermills
A typical watermill used a wheel turned by a stream. There were two main arrangements. In an undershot mill, the stream flowed beneath the wheel, pushing its lower paddles. In an overshot mill, water was channeled over the top of the wheel, which usually made better use of the water but required a drop in the land. Millers often built dams, ponds and channels, called leats, to keep the supply steady. Gears transferred the turning motion to the millstones.
Mills were so common that they appear throughout the documents of the time. The Domesday survey of England in the late eleventh century records several thousand mills, which indicates how normal they already were in one country by then. Exact numbers vary depending on how the entries are counted.
Tide mills, which trapped incoming water in a pond and released it as the tide fell, were used in some coastal areas, giving power where rivers were weak.
Windmills
Windmills are first recorded in western Europe in the later twelfth century. Where they first appeared, and how far the idea came from elsewhere, is debated. Windmills with a different design existed in parts of the Islamic world, but whether the European type developed independently is uncertain.
The early European type is called a post mill. The whole body of the mill, with the sails and machinery, was mounted on a large central post so that the miller could turn it to face the wind. Later, tower mills were built with a fixed stone body and a rotating cap carrying the sails, which was more stable and could be larger. Windmills were most useful in flat, dry or windy places where rivers were scarce, such as parts of eastern England, Flanders and the lands around the North Sea.
Beyond grinding grain
Once a mill supplied rotating power, people found other uses for it. By converting the circular motion into up-and-down motion with cams, mills could drive hammers and other tools.
- Fulling mills. In the cloth trade, woven wool was beaten in water to thicken and clean it. Previously this was done by workers treading it with their feet. Mills with wooden hammers took over the job, which sped up production. The wool trade was a major industry in places like England and Flanders, so the effect was significant.
- Forge hammers and bellows. Water power could work heavy hammers and blow air into furnaces, which made it easier to work iron in quantity. Techniques of this kind belonged to the broader world of the blacksmith forge but allowed larger-scale production.
- Other processes. Mills were adapted for tasks such as sawing timber, crushing bark for tanning, pressing oil, and, in the late Middle Ages, making paper.
Who owned the mills
Because a mill was expensive to build and needed water rights, mills were typically owned by lords, monasteries or towns. Under the manorial economy, a lord might require villagers to bring their grain to his mill and pay a fee, often a share of the flour. This right is sometimes called a monopoly or suit of mill. It could be a source of steady income for the lord, but it was often unpopular, since tenants resented the cost and sometimes suspected the miller of taking too much. Millers appear in medieval literature with a reputation for sharp practice, though that may reflect the social tension as much as the facts.
Disputes over mills also show how valuable they were. Blocking a stream for a mill could affect users downstream, and some cases ended in court or in conflict. Peasants sometimes tried to use hand querns in secret to avoid the fee, and lords sometimes sent officials to seize them. Such stories are known from several regions.
Effects on work and society
The influence of mills should be described with care, because evidence is uneven and varied by place. Even so, several effects are widely accepted.
- Saved labor. Grinding by hand was slow, and mills freed time that could be spent on other work.
- Supported towns. Medieval towns needed large and regular supplies of flour and finished cloth, and mills helped supply them.
- Encouraged specialized trades. Millers, fullers and millwrights developed skills in carpentry, gearing and water management.
- Shaped the landscape. Mill ponds, channels and windmill mounds became fixtures of the countryside, and many settlements grew up around them.
- Created conflict. The expense and lord’s control of mills added to disputes between peasants and landlords, especially those involving unfree peasants who owed fixed duties.
Mills did not abolish hard physical work, and many other tasks remained entirely manual. Still, harnessing natural power on a wide scale marked a real shift. It showed that moving water and wind could do work for a community, an idea that would be extended in later centuries.