This chapter reviews important periods in the GMB's history in order to give context to the union's recent work at BHX4. Given the highly international character of the workforce at BHX4, particular attention is given to the GMB's record of responding to the needs of workers with a migrant background, and the closely related issues of race and racism. Consistent with the GMB's own practice, this book uses ‘Global Majority’ to refer to workers of African, Asian or Latin-American descent. This is followed by a discussion of the GMB's organizing strategy at BHX4, set in the context of relevant parts of the literature on organizing.

The GMB is the third-largest trade union in the UK, with more than half a million members, and its origins date back to the Gas Workers and General Union founded in 1889. Its rapid success in building its membership among the highly diverse and precarious workforce at BHX4 contradicts a widely held idea that Britain's large, formalized trade unions are poorly suited to grassroots organizing and tend to seek class compromise in defence of a labour elite, in contrast to the agile militancy of smaller ‘indie’ trade unions. Some writers have suggested that traditional unions like the GMB have been learning from these indie unions, and also that the changing composition of the working class in Britain and the proliferation of precarious employment have forced unions to change in order to stay relevant.