While many people think that Rolex invented the first automatic wristwatch, it was actually a different brand. John Harwood, a british watchmaker, patented the first automatic or selfwinding wristwatch in 1923. The first Harwoods went on sale in 1928. As far as I can find out, it was Fortis who actually produced about 30000 Harwood watches until 1931 when Harwood had to shut their business.
Peter Peter, former Owner of Fortis, met with Harwood Junior in the 1980s and produced an unknown number of Harwood watches at that time.
So here is a bit of history of the first automatic wristwatch. The early beginnings were not as glorious as some may think. In 1930 Rolex improved the automatic winding from a bumper to a selfwinding bidirectional rotor. A major improvement which kind of lasts up to today although there have been improvements over time.