Sir W.G. Armstrong, Whitworth and Company Ltd was formed in 1897 by the merger of Joseph Whitworth and Company with Armstrong Mitchell and Company, which itself had been formed by the merging of W.G. Armstrong and Co with Charles Mitchell and Co in 1882. This new company manufactured a wide range of products including hydraulic equipment, bridges, armaments and ships. Its shipyards produced many merchant vessels such as freighters, tankers, dredgers and icebreaking train ferries for Lake Baikal. They also constructed warships for the Royal Navy, Imperial Russian Navy, Imperial Japanese Navy and United States Navy, including the first polar icebreaker ‘Yermak’, which was constructed for the Russian Navy and launched in 1898.

Initially the new company was headed by William George Armstrong but following his death in 1900 Andrew Noble was appointed as chairman. Also, at this time production of cars and truck would begin, in order to diversify production following the end of the Boer War and the resultant drop in the demand for artillery. Initially these were designed by other companies, but this would switch to inhouse designs later on.

In 1913 an aerial department was formed to begin production of aeroplane and airships. This department produced a number of different designs during the First World War and in 1920 it became a subsidiary under the name Sir W.G. Whitworth Aircraft Ltd.

Following the end of the First World War the company again recognised a need to diversify due to a greatly reduced demand for munitions. As part of this it formed a subsidiary under the name Armstrong Whitworth Development Company. This acquired Siddeley-Deasy, which became known as Armstrong Siddeley Motors, as well as a controlling interests in Crompton and Co and A and J Main and Co. The Scotswood Works would also be repurposed to build railway locomotives. This proved successful due to the modern machinery that had been installed and would produce 1,464 locomotives until 1937 when it was converted back to armament manufacturing. In addition to the steam locomotives common at the time this figure also included diesel locomotives and railcars due to a licence acquired for Sulzer.

1920 not only saw the aerial department’s reorganisation into the Armstrong Whitworth Aircraft Company but also the purchasing of a controlling interest in Pearson and Knowles Coal and Iron Co, along with its subsidiary Partington Steel and Iron Co. Later, in 1922, the company would also form the Newfoundland Power and Paper Utilities Corporation in order to finance a paper mill and in 1925 Boving Engineering Co was purchased.

By 1926 the company was suffering financially. Due to the Newfoundland company going over budget and not achieving its productions goals the company was suffering from a greatly reduced cash flow. In the first 11 months of 1926 its losses amounted to £625,767 and by 1927 the decision had been take to merge the defence and engineering businesses with that of Vickers in order to create a new subsidiary of Vickers Armstrong. The ownership of this would be split so that Vickers held 2/3 and Armstrong-Whitworth held 1/3. The Armstrong Whitworth Development Company would also be sold, and it became the Armstrong Siddeley Development Company following its acquisition by J.D. Siddeley, although Armstrong-Whitworth still held a substantial shareholding and also retained the Pearson and Knowles Coal and Iron Company.

Despite these actions heavy financial losses continued and, although they were offset by the sale of the company’s shares in the Armstrong Siddeley Development Company, they still resulted in a serious reduction in capital. As a result, the decision was taken to form two new companies to take over the activities of the original one. These were Sir W.G. Armstrong Whitworth and Company (Engineers) Ltd, which took over the general engineering business, and Sir W.G. Armstrong Whitworth and Company (Shipbuilders) Ltd, which took over the Devon, Walker and Tyne shipyards. A holding company was also formed to manage these, Armstrong Whitworth Securities Company Ltd. In 1930 a third company was added to the group, Sir W.G. Armstrong Whitworth and Company (Ironfounders) Ltd.

Beyond this the 1930s saw a winding down of the Armstrong-Whitworth group’s activities. In 1935 Vickers bought the remaining shares of Vickers-Armstrong and in 1937 Sir John Jarvis acquired Sir W.G. Armstrong Whitworth and Co (Ironfounders) Ltd to relieve unemployment on Tyneside. By 1937 the group had also ended production of locomotives and only the engineering subsidiary remained. This was sold in 1943 and the group was liquidated.