Leonardo da Vinci designed a windmill with rotating blades to generate power from wind.
His mechanical studies included wind-powered devices in which blades turned around an axle as air flowed against them. Through gears and shafts, rotational motion could be transferred to useful work such as grinding or pumping. The basic idea follows the same energy conversion used by historical windmills: moving air turns a rotor, and the rotor drives machinery.
Leonardo did not invent the windmill. Windmills were already established in parts of Europe by the late Middle Ages, while earlier wind-powered mills had existed in Persia for centuries. His contribution was to analyze machines and propose refinements in form, gearing, and transmission. These drawings are sometimes confused with his aerial screw, but the purposes differ: a windmill extracts energy from wind, whereas an aerial screw was conceived as a machine that might rise by rotating a helical surface. Leonardo's windmill concepts were designs on paper, and there is no evidence that one of his particular versions became a standard working mill. Modern wind turbines use aerodynamic blades and electrical generators, making them descendants in principle rather than direct copies of his Renaissance machine.