Walter T Glover established his wire manufacturing company in 1868, occupying premises at the Bridgewater Street Iron Works in Salford. W T Glover & Co, known as Glover’s, originally made cotton-covered and braided, insulated copper wires for use on bell, signalling and telephone circuits. As trade developed, the company moved to the Springfield Lane Cable Works in 1880. At this time, factories and larger private homes were beginning to install electric lighting, which required better insulated cable. Glover's started to manufacture cables covered with between one and three layers of rubber strip, waterproof tape and compounded cotton braid. In the late 1880s, Glover's began to make lead-sheathed cables for underground use. The company became a limited company and moved to Trafford Park in 1898, securing the exclusive rights for the supply of electricity to all the roads, streets and premises of Trafford Park. In June 1919, Vickers Ltd took over Glover's. Although Vickers held most of the shares, Glover's kept its name and management. In 1929 the Vickers group reorganised and sold its shares in Glover's to Sir Tom Callendar of Callendar Cable and Construction Co. Some shares later went to W. T. Henley's Telegraph Works Ltd. and British Insulated Cables. In 1945, Glover’s became part of British Insulated Callenders Cables Limited, following the merger of Callenders Cable and Construction Co and British Insulated Cables. During the 1950s, Glover’s developed high voltage submarine power cables, used to link centres of population with sources of generation. The parent company formed a subsidiary, BIC (Submarine) Cables Ltd, to manufacture and install the Glover’s cables. Glover's submarine cables linked England and France, and the north and south islands of New Zealand. Increasing competition from other cable manufacturing companies resulted in the south side of Glover’s Trafford Parks works integrating with the newly formed Wiring and General Cables Division of the British Insulated Cables Company (BICC). The Trafford Park factory closed in 1970, but the Glover’s brand continued as part of BICC.

Metropolitan-Vickers Electrical Co Ltd was the new trading name given to British Westinghouse Electric and Manufacturing Co on 8 September 1919. The predecessor company had sold its controlling share to the Metropolitan Carriage Wagon Co in 1916 in order to gain membership of the Federation of British Industries. In 1919, Vickers acquired the Metropolitan Carriage Wagon Co, along with its controlling share in British Westinghouse, prompting the change in name to Metropolitan-Vickers Electrical Co Ltd. The American owned British Westinghouse had established its English operations at Trafford Park in 1899, and Metropolitan-Vickers Electrical Co Ltd continued on the same site from 8 September 1919. The company was initially known for its electricity generators, later diversifying into the manufacture of steam turbines, switchgear, transformers, electronics and railway traction equipment. The passing of the Electricity (Supply) Act in 1926 provided a boost to the company’s post-war fortunes, with the creation of the National Grid generating demand for the company's products. In 1928, Metropolitan-Vickers Electrical Co Ltd merged with its rival British Thomson Houston Co Ltd, retaining both names for trading purposes. The following year, on 4 January 1929, Associated Electrical Industries Ltd (AEI) acquired Metropolitan-Vickers Electrical Co Ltd and the British Thomson Houston Co Ltd. Again, both trading names were retained, and a fierce rivalry was established between the firms which the parent company was unable to control. In 1931, Sir Felix Pole joined Metropolitan-Vickers Electrical Co Ltd as its new chairman. He oversaw a period of expansion for the company leading into the Second World War. In 1939, seeking a more concise name for the company, the Board of Directors decided upon Metrovicks, which became interchangeable with the official company name of Metropolitan-Vickers Electrical Co Ltd. Under Sir Felix Pole's chairmanship, Metropolitan-Vickers developed new products for the aviation industry and during the war was one of the sites where Lancaster bombers were built. In 1941, the company developed the first British axial-flow jet engine, the Metrovick F.2. Following the Second World War, the company appointed Oliver Lyttelton as chairman, with the aim of increasing the efficiency and productivity of AEI. Despite his success in achieving this aim, Lyttelton was unable to resolve the commercial rivalry between Metropolitan-Vickers Electrical Co Ltd and the British Thomson Houston Co Ltd. During his second period as chairman, from 1954-1963, Lyttelton, now Lord Chandos, oversaw the development by Metropolitan-Vickers Electrical Co Ltd of the first commercial transistor computer, the Metrovick 950. Chandos also resolved to extinguish the competition and internal divisions between Metropolitan-Vickers Electrical Co Ltd and the British Thomson Houston Co Ltd, and both company names ceased to be used from 1 January 1960, with all subsidiaries going on to trade under the name of Associated Electrical Industries Ltd.