Although automatic watches were invented in the late 1700s by a Swiss watchmaker named Perrelet and improved around 1800 by Breguet, they were not very successful until the watch began to migrate from the pocket to the wrist. Wearing a watch on the wrist, in fact, takes much better advantage of the potential of this innovation, as it allows much more movement than a typical pocket watch. But the concept of the automatic watch really took off at the beginning of the 1920s, when watches started to have to counter the effects of water – and the typical crown, used to wind the watch, was a major issue.
The inventor who created the first working automatic wristwatch ready for production was a British watchmaker, John Harwood, who around 1923 developed the design of the bumper movement, licensed his movement to some manufacturers (like AS Schild and Fortis), and founded his eponymous company in 1928 to market it.
He was followed by Rolex, which around 1930 refined the concept of the central rotor as an improvement over Harwood’s bumper design, patented it, and mounted it on its Oyster Perpetual line of water resistant watches.
Thanks to the added convenience of not having to recharge the watch constantly – Rolex’s design had 36 hours of power reserve, which was an excellent result back then - the automatic movement design spread quickly among wristwatches from the 1930s onwards. Both automatic solutions would be improved during the following years, to come to the present day, with centrally mounted rotors becoming dominant because of their greater efficiency, and the possibility of being mounted afterwards as a module.