Chapter 5 looks at Amnesty’s development in the mid-1960s, and in particular the major crisis that engulfed the organisation in 1966-1967 over its involvement in the crises in Aden and Rhodesia. The chapter opens with an overview of the crisis, which resulted in the departure of Peter Benenson. Two key aspects are then explored in detail; first, Amnesty’s relations with the British state, in particular the secretive Information Research Department of the Foreign Office, and, secondly, Peter Benenson’s long-standing engagement with the problems of southern Africa. It is argued that the crisis was due, in part, to Benenson’s attempt to devise new mechanisms for non-governmental intervention. The chapter concludes with an account of the drive to reform and professionalise Amnesty under the leadership of Martin Ennals.