It is a joint brand.

As the two largest companies producing flattop guitars in the United States, Gibson and Martin have reluctantly lost the market for mid-range and low-end guitars because they are very popular in the United States. It was difficult to produce guitars that were both cheap and of good quality, and they were unwilling to compromise on quality because of price, so both companies set up branches overseas. Martin acquired the Swedish company Levin to manufacture mid-range guitars, and used the Japanese company Sigma to produce low-priced guitars. Gibson began branding a series of guitars produced in Japan under the Epiphone (named after Epi Stathopoulo, who died in 1957) in 1969.