The beginning of work on the development of self-loading rifles in Ceska zbrojovka in Strakonice is connected with the name of Emanuel Holek (1899–1982) and director Gustav Benes (1880–1932), who designed a prototype with the designation HB between 1925 and 1927. The development line went through two stages of S rifles (named after Strakonice, their place of origin) and resulted them being produced at the factory, referred to as Automatic Rifle III, in official documents listed as CZ M 35. It was developed during 1933 and, like previous variants, was continuously tested by the Military Technical and Airforce Institute (VTLU). Following durability tests with one prototype, conducted in the first half of 1935, the Ministry of National Defence ordered 10 samples for wider trials. Tests at Plavecke Podhradie, conducted in December 1935 and again in September 1937, did not lead to clear results and the Ministry of National Defence’s interest was focused on another, more promising design from Ceska zbrojovka, the CZ Model 37 rifle.