This text examines the role of the Association of Chief Police Officers (ACPO) within British policing and police policy-making. Based on the first ever empirical study of ACPO, involving interviews with over 60 members of ACPO and many others connected with British policing, the book charts the changing position of ACPO over time and the influence which ACPO has over both policing policy and criminal justice policy more generally. In doing so it draws from a range of themes including patterns of police governance and accountability, police culture and policy networks. It concludes with a critical assessment of the doctrine of "constabulary independence". The book provides an insight into the workings of a body which represents the most senior police officers in the land.