1892 After the Edison and Swan Lamp patents expired, GEC established a lamp factory - see Robertson Electric Lamps.
1905 Hugo Hirst learnt of the development of Tungsten filaments for lamps in Austria-Hungary, went to investigate and acquired rights .
1906/7 Hirst established a factory in U.K. to manufacture lamps, Osram Lamp Works, having offered one-third shares to the Austrian and German patent holders .
1908 Announcement of a reduction in price of Osram electric lamps; manufactured by Wolfram (Tungsten) Lamps Ltd; GEC had sole selling rights in U.K. and Colonies , importing Osram filaments from Germany.
1908 Displayed a hand lamp, developed to meet recommendations for improved safety of such lamps, at the Manchester Electrical Exhibition .
1909 Osram factory at Hammersmith completed; quality of the product said to be as good as that from the Continent.
1913 Tungsten Lamp Association was formed by 4 companies, including GEC and BTH.
1915 Osram Lamp Works, Robertson Lamp Works and Lemington Glass works were amalgamated by GEC.
1917 GEC was part owner of the Osram-Robertson Lamp Works Ltd and had managed the Works since opening. Purchased further shares in Osram-Robertson Lamp Works Ltd .
1919 GEC took over Osram, including the Osram-Robertson Lamp Works.
1919 Electrical Lamp Manufacturers Association formed. 6 other companies had joined and 7 others were non-associates.
1919 Marconi-Osram Valve Co formed as company owned jointly by GEC and Marconi's Wireless Telegraph Co; it took over GEC's valve factory.
1920 Name changed to M-O Valve Company
1920 Jan. Physical and Optical Societies Exhibition. Exhibited wireless telegraphy.
1920 Board of Trade report into the "Electric Lamp Combine" recognised the Electrical Lamp Manufacturers Association was set up principally in the interests of BTH, GEC and Siemens Brothers and Co.
1925 Advertisement for Marconi Valves by the Marconiphone Co and GEC 'Made at the Osram factory'.
1930 Extensive application of public lighting; development of photo-electric controls; development of lamps for cinema projectors
1931 Advert for new, improved valve filament for use in battery radios.
1939 The company had made advances in discharge lamps for street lighting.
1956 GEC purchased EMI's share in the M-O Valve company.