Horex is a German motorcycle manufacturer. It was founded in 1920 by the Rex glassware company, which conflated Homburg and Rex to create the brand name. The headquarters was in Bad Homburg.Horex built motorcycles with Columbus four-stroke engines from Oberursel. In 1925 Horex and Columbus merged. Horex developed a range of models with single-cylinder Columbus engines from 250 cc to 600 cc. In 1933 it added two parallel-twin models: the 600 cc S6 and 800 cc S8.