In August 1936, the Catalan government (la Generalitat de Catalunya) created the Commission of War Industry (Comissió de la Industría de Guerra), whose task was to ensure the start-up of arms production for the needs of the Republican forces. In Olot, Catalonia, at plant number 15, a completely unique design of submachine gun was created, which became one of the iconic weapons of the Spanish Civil War. The submachine gun was named Fontbernat, but was also known as Labora or Olot, depending on the place of manufacture.
The Fontbernat submachine gun was produced in Olot between 1937 and 1938, and the pieces produced differed from each other in a number of small details and markings. The total number of submachine guns produced remains unclear to this day as production records were destroyed during the war.
The stated quantity of around 1,000 pieces is disputed by the production numbers of the few surviving examples.