In recent times, groupwork with people supervised by probation staff has become a central part of the government driven effective practice strategy: it has not always been so. For most of the history of the probation service, groupwork, with some notable exceptions, has been a peripheral activity sustained mainly by the energy and commitment of enthusiastic practitioners. Moreover, it has been a relatively neglected part of the story of probation. This, then, is the first of two articles that set out to tell that story. This first part describes the development of groupwork from the late mission period (characterised by moral exhortation) to the era of professionalisation (characterised by casework treatment). In so doing, it seeks to emphasise the importance of groupwork's contribution to the epistemological history of the supervision of offenders in the community.Probation is characteristically and traditionally an individual type of treatment.So wrote Hugh Barr 1 at the beginning of his survey of groupwork in 1966, and the outcome of his survey serves to confirm that axiom. He wrote to 125 probation areas in England, Wales and Scotland, and of the 117 who replied 31 indicated that some form of groupwork was being undertaken in their service (27 in England and Wales and four in Scotland). Subsequent surveys suggest a gradual increase in this form of work over the next two decades: in a review of chief probation officers' annual reports Davies (1976) found 'wives' groups' (at 66%) the 'single most common non-statutory innovation compared with a decade ago' (p. 87); in a later historical review, Senior (1991) asserted, '[t]he decade between the two Criminal Justice Acts 2 witnessed a huge spurt in groupwork activity ' (p. 285);and Brown et al. (1982) expressed the view that 'groupwork is practised more extensively in social services and probation and after-care settings in the South-West than it was 10 or even 5 years ago' (p. 588). Twenty-seven years after Barr's survey, Brown and Caddick (1993) drew together a diverse range of examples of probation work with groups in an edited volume which included a survey of 56 probation areas by Caddick 1993. In it, 43 responded by supplying 69