This thesis explores the workings of co-operation. It proceeds by way of a two-case comparative study, where the units of comparison are local consumer co-operatives: the Newcastle upon Tyne Co-operative Society Ltd., situated in the north-east of England, and Konsumentföreningen Solidar in Malmö, in the south-west of Sweden. We get to follow the two societies through minutes from member meetings, and from several other data sources, from their dates of birth to 1970. This material is utilised for cross-case and within-case comparisons as we follow the interaction between the societies and their environments, between organisational structure and decision-making, and between different factions within the societies. The primary purpose is to charter, understand, and explain the complexities brought out by the empirical inquiry. But in doing so, we also discern more general underlying principles for variations in the workings of co-operation. While this makes the thesis into an exploratory endeavour, it also contains an attempt to map the historiography of co-operation in Britain and Sweden: themes and research questions are construed so as to make a contribution to both literatures. One such contribution is the description and analysis of two separate organisational logics, of their dynamics, conditions, effects, and development over time.