Montres TUDOR SA is a Swiss manufacturer of luxury wristwatches based in Geneva. Registered in 1926 by Hans Wilsdorf, the founder of Rolex SA, the brand remains a sister company to Rolex, both companies being owned by the Hans Wilsdorf Foundation. The Tudor trademark was registered in 1926 by Swiss watchmaking company “Veuve de Philippe Hüther” on behalf of Hans Wilsdorf, the founder of Rolex watches. In 1936, Wilsdorf took it over himself and went on to found the company Montres Tudor SA in 1946. The Tudor brand aimed to offer a more affordable watch that would preserve the Rolex reputation for quality. Tudor watches were originally equipped with off-the-shelf movements while using Rolex quality cases and bracelets, allowing them to provide the reliability and dependability of a Rolex but at a lower price. The adoption of the Oyster case and self-winding rotor facilitated Tudor's move into the production of tool watches. Tudor became especially well known for its tool watches, producing watches for professional divers and the military. Between the 1960s and 1980s, several navies issued Tudor Submariners to their divers, including the US Navy SEALs, and the French Marine Nationale (French Navy).