Swan Electric Light Co
1880 Joseph Swan formed a company for the manufacture and development of the lamp, with Charles Henry Stearn as technical manager.[1]. Began commercial production of filament lamps. 1,200 of the lightbulbs were used to illuminate the Savoy Theatre in London to the astonishment of the audiences.
In America, Thomas Edison had been working on copies of the original Swan patent, trying to make the lamps more efficient. Though Swan had beaten him to this goal, Edison obtained patents in America for a fairly direct copy of the Swan light, and started an advertising campaign which claimed that he was the real inventor. Swan, who was less interested in making money from the invention, agreed that Edison could sell the lights in America while he retained the rights in Britain.
1882 Swan's first company was superseded by a larger company (presumably Swan United Electric Light Co).
1883 Amalgamation of the Edison Electric Light Co and the Swan United Electric Light Co to form Edison and Swan United Electric Light Co; company incorporated on 26 October. Known commonly as "Ediswan" the company sold lamps made with a cellulose filament that Swan had invented. Variations of the cellulose filament became an industry standard, except with the Edison Co.[2][3]. Several lighting orders in parts of London were transferred to the new company from the constituent companies.