This study assesses the impact of the years 1914 to 1921 on British labour organisation and industrial relations. By combining local studies with national sources the thesis provides a measure of corrective to the 'view from the centre' approach to twentieth-century labour history and a new perspective from which to view the period. In Section I comparative studies of Sheffield, Pontypridd and Liverpool offer explanations for regional differences in the development of labour organisation. These local studies focus upon the consolidation of labour forces and the dimensions, timing and explanation of Labour's fluctuating electoral fortunes. A second Section considers the changing power relationships between officers, activists and membership in the Co-operative Union, National Union of Railwaymen, Associated Society of Locomotive Engineers and Firemen and the South Wales Miners' Federation. A re-evaluation of the role of labour leadership contributes to a critical appraisal of 'rank and filist' interpretations of labour history. In studies of the railway and mining industries it is argued that the centralisation of industrial relations was not simply imposed upon labour by employers and the state. Trade unions played a larger and more positive role in the development of a centralised industrial relations system in these industries than is generally acknowledged. The thesis concludes with a contribution to the current debate between the'revolutionary' or 'rank and filist' school and its critics in thefollowing areas: the causation of labour unrest; the nature of state intervention; the character of labour leadership and the causes andtiming of the rise of labour.