The six riots were the most serious of those that occurred during April and took place at Manchester, Glen Parva, Dartmoor, Cardiff, Bristol, and Pucklechurch. Information was gathered from hearings; letters from inmates, correctional personnel, and others; document reviews; and meetings with correctional personnel, inmates, individuals, and organizations. Results indicated that the causes were overcrowded and unsanitary prison conditions, negative inmate-staff relations, inadequate attention to prisoners' rights, inadequate personnel training, and a lack of leadership in the Prison Service. Recommended changes include continued management reforms, improvements in inmate-staff relations and staff-management relations, more inmate visits and other programs, and other measures. Detailed descriptions of each prison's disorders, photographs, lists of meeting participants, and related materials are included.