In 1921 the company was formed as Amalgamated Photographic Manufacturers Ltd., London, or APM 1921. It was derived from a merger of seven British companies (APM 1921, the original seven companies, comprised Kershaw Optical Co. Ltd., A. Kershaw & Son Ltd., Marion & Foulgar Ltd., Rotary Photographic Co. Ltd., Rajar Ltd. (founded 1901), Paget Prize Plate Co. Ltd., Marion & Co. Ltd.). In 1928 four of the seven, the ones which were in the film business, became APeM Ltd. (Amalgamated Photographic Equipment Manufacturers) and subsequently became part of Ilford. Based at 3 Soho Square, London W.1.