Technology & Medicine › Medieval
Windmill
c. 900 (Persia); Europe c. 1185· Invention or discovery· Tools, energy & materials
Mostly agreedGood evidence; some details, dates or numbers uncertain.
Machines that harnessed wind to grind grain and pump water, first recorded in Persia around 900 and in England in 1185.
See it on the Technology & Medicine map →How it works
Persian windmills in Sistan, described by geographers in the 900s, had sails on a vertical shaft, set behind walls that funnelled the region's strong, steady wind. European post mills, first recorded in Yorkshire in 1185, were a different design: sails on a horizontal axle, with the whole mill house turned to face the wind. The Dutch used them to pump water off reclaimed land and to saw timber; the Netherlands had roughly 9,000–10,000 by the mid-1800s.
Why it mattered
It brought mechanical power to places without fast rivers, made Dutch land reclamation possible and, reborn as the wind turbine, now supplies a fast-growing share of electricity.
How we know
Arabic geographers such as al-Istakhri and al-Masudi, English charters from the 1180s, surviving mills, and Dutch records and paintings.
Still unknown or debated
Whether Europe's windmill was copied from Persia or invented independently is debated; the designs differ so much that many historians favour independent invention.
Connections (3)
▸Watermill was joined by the WindmillMostly agreed
The connection
Millwrights already knew how to turn a wheel's rotation, through gears, into grinding power. The windmill applied the same millstones, and in Europe the same gearing, to a different energy source. It spread where rivers were slow, seasonal or frozen, such as Persia's dry east and the flat lands of eastern England and the Low Countries.
When and how
Sistan, eastern Persia, by the 900s; England and northern France from the 1180s.
How sure are we?
European post mills used the same right-angle gearing and millstones as Roman-style watermills; early records show both serving the same estates.
Debates and open questions
Whether the Persian windmill was inspired by water wheels at all, and whether Europe's came from Persia, is uncertain.
▸Windmill was replaced as a power source by Watt's steam engineWell documented
The connection
For centuries, wind and water mills were the main mechanical power for grinding grain, pumping water and driving workshops. They worked only where and when wind blew or rivers flowed. Steam engines burned coal anywhere, at any hour, so industry could move to cities and coalfields, and mills slowly declined.
When and how
Britain and the Netherlands, late 1700s to late 1800s; wind and water stayed important in rural areas into the 1900s.
How we know
Power estimates show steam overtaking water power in British industry around 1830–1850; water wheels, more than windmills, were steam's main rival.
Debates and open questions
How much coal-fired steam mattered to early industrial growth is debated; some economists estimate it added little to productivity before about 1830.
▸Windmill returned as wind turbines alongside Cheap solar, batteries and electric carsWell documented
The connection
Windmills ground grain and pumped water for about a thousand years. In 1887–88 James Blyth in Scotland and Charles Brush in Ohio used them to make electricity. Danish engineers refined the three-bladed turbine in the 1970s–80s; today's machines often stand over 150 meters tall and, alongside solar, supply much of the world's new power.
When and how
Scotland and Ohio, 1887–88; Denmark's turbine industry from the 1970s; wind farms worldwide today, led by China, the US and Europe.
How we know
Blyth's and Brush's machines are described in period engineering records; the Danish design lineage, through makers like Vestas, is well recorded; Ember and the IEA track wind output.
Debates and open questions
How far wind can grow depends on grid connections, local opposition, offshore costs and supply chains; recycling old turbine blades is still largely unsolved.