The prison is everywhere. Yet it is not everywhere alike. For all its apparent universality, the prison continues to display marked, sometimes staggering, divergences in how it operates from one country to the next. What is permitted as a matter of course in one prison system, such as conjugal visits, modern interiors, literal warehousing or extended segregation, are each seen somewhere else as peculiar, utterly inexplicable, even offensive uses of imprisonment. These differences in prison practice and culture are not only regional; a prison system is liable to evolve and change over time. The present imprisonment arrangements in one place may bear little resemblance to how they were organised only a few decades earlier. Why is this? Why does the prison differ and transform as it does? This book sets out to explore these questions by conducting a comparative, historical and sociological study of adult male imprisonment and political culture in Ireland and Scotland from 1970 until the 1990s. I begin from the contention that prisons are social and political institutions. This requires asking: What are the social conditions that give rise to specific penal measures? What cultural values make certain uses of confinement permissible and appropriate while rendering others unacceptable? How does punishment shape social order, reproduce state power and enforce cultural norms? How does the prison relate to other penal, social and welfare institutions (Garland 1991:119)? To understand how exactly social, political and cultural forces find themselves realised in actual prison practices requires a much greater attention to the policymaking that shapes, remakes and maintains prison systems. In exploring these matters, this book aims to recover and compare the meanings, ideas and sensibilities that made Ireland and Scotland’s distinctive penal cultures possible at the end of the twentieth century.