John Harwood created the first practical self-winding wristwatch, patented in 1923.
Harwood, an English watchmaker, developed a winding system using a rotor that moved as the wearer’s arm moved. The rotor wound the mainspring without requiring the crown to be turned manually, although the design used a bumper that moved through a limited arc.
Harwood’s watch was patented in Switzerland in 1923 and entered production later in the decade. Its design helped establish the idea of automatic wristwatch winding before later full-rotor systems became dominant.
A common mix-up is crediting Rolex with inventing automatic winding. Rolex’s 1931 Perpetual mechanism was highly influential because its rotor could turn freely in both directions, but it came after Harwood’s earlier practical system.