This article completes a two-part history of groupwork in probation during the 20th Century. The first part traced the development of this aspect of probation work as an important part of the theory and practice of supervising probationers in the community. This second part purports to show the burgeoning significance and relevance of work with groups, and how it encouraged a more collaborative approach focused more specifically on the offence. More particularly, it explores its contribution to, on the one hand evidencebased practice and on the other, increased governance both of probationers and of probation policy and practice.The first part of this history of groupwork 1 showed how in the first half of the 20th Century its place in the training curricula of probation officers had been established, 2 and its practice 'transformed from the use of activity as a vehicle for moral influence to a kind of collective casework treatment' (Vanstone 2003, p.78). Moreover, it argued that by the 1960s groupwork practice had opened a window on the non-treatment paradigm later to be conceptualised by Bottoms and McWilliams (1979). This second part continues the story of the movement of groupwork from the margins of probation activity to a central position of influence. It is a story characterised by four features: firstly, the continuance of treatment based on a more collaborative worker-client 3 relationship and the emergence of the client as an agent in the process of change; second, the renewal of emphasis on the offence as a focus of probation work; 4 third, the development of effective practice; and finally, increased governance both of offenders and of probation policy and practice (Senior 1991;Robinson 2000). It opens at the time of the developing critique of the treatment model. 5