The Amalgamated Union of Building Trade Workers (AUBTW) was established 1 January 1921 by the amalgamation of the Operative Society of Masons, Quarrymen and Allied Trades of England and Wales, the Manchester Unity of Operative Bricklayers' Society and the London Order of Operative Bricklayers' Society. It merged with the Building and Monumental Workers' Association of Scotland in 1942, the National Builders' Labourers' and Constructional Workers' Society in 1952, the National Society of Street Masons, Paviors and Road Makers in 1966 and the Amalgamated Slaters, Tilers and Roofing Operatives in 1969. On 1 July 1971 it amalgamated with the Amalgamated Society of Woodworkers and Painters to form the Amalgamated Society of Woodworkers, Painters and Builders. In December 1971 the Society changed its name to the Union of Construction, Allied Trades and Technicians.
Reference: Leslie M. Wood, 'A union to build. The story of UCATT' (London: Union of Construction, Allied Trades and Technicians, 1979).