David Colville and Sons
Colvilles, of Dalzell Steel Works and Ravenscraig.
Motherwell, near Glasgow.
1871 Company founded by David Colville. The works dates from 18th October 1871 and started as a malleable iron works, manufacturing bars, beams, etc.
1880 The firm switched to steel production.
1888 Glasgow International Exhibition. Siemens plates, rolled bars and hammered blooms. 
1895 Incorporated as a private limited company.
1914 Manufacturers of steel and iron, Siemens open hearth mild steel, high tensile steel and nickel steel, boiler, ship and special quality plates, angles, bulb angles, channels, zed bars, tee bars, rounds and other sections, billets, blooms, ingots for forgings etc. 
1915 Colvilles took over the Clydebridge Works
1916 Colvilles had also purchased Glengarnock Iron and Steel Co in June 1916, and as submarines had become active, the Ministry requested Colvilles to undertake large expansions, to meet the acute demand for steel plates to build Standard Ships. The enlargement of both works began in October 1916, at a cost of £1½ million.
1919 The Engineer published a summary of the company's history, read it here.
1930 Became a public company.
1931 the Lithgow brother agreed to merge their holdings in James Dunlop and Co with David Colville and Sons, as a consequence of which they joined the board of the Colville companies, forming Colvilles. It was decided to centralize pig iron manufacture at the former Dunlop's Clyde Iron Works. This resulted in the blast furnaces at Glengarnock closing down and the old rolling mill was also closed down.
1934 the Lithgow brothers bought the shares of the Steel Company of Scotland. Their ownership of these shares posed a threat to the growing monopoly of the Colville group in supplying the shipbuilding market, and encouraged the Colville group to incorporate the Steel Company of Scotland in its rationalization scheme.
1937 Colvilles restructuring begins which will ultimately lead to the building of the Ravenscraig Steelworks.
1937 Steel and iron manufacturers. 
1954 Ravenscraig Steelworks opened by Colvilles at a cost of £20,000,000, with 2 batteries of 35 coke ovens, a blast furnace and melting shop with 3 furnaces. Colvilles older furnaces to be demolished.
1955 Public offer for sale of shares in the company held by the Holding and Realization Agency.
1957 Ravenscraig Steelworks Construction complete.
1960 Advert- Colvilles, 195 West George Street, Glasgow C.2.
1961 Ten subsidiaries with works at Motherwell, Cambuslang, Glengarnock, Glasgow, Bellshill, Uddingston and Coatbridge. Employ 10,900 persons. 
1967 Became part of British Steel.
Sources of Information
- History of Clydebridge
- The Engineer of 27th April 1888 p338
- The Engineer 1957/02/08
- 1914 Whitakers Red Book
- 1937 The Aeroplane Directory of the Aviation and Allied Industries
- Hansard 19 February 1951
- The Times, 8 February 1954
- The Times, 28 August 1954
- The Times, 17 January 1955
- 1961 Guide to Key British Enterprises