Prisons, like prostitutes, have always been with us but, over time and place, have changed radically in conditions, attributes and functions, as well as in their name, character and rationale. The period of our consideration spans the Anglo-Saxon era to the present day; the place is largely confined to the constituent parts of the British Isles.

Du Cane Road in West London, which bisects the lower-middle-class area of East Acton, serves a highly symbolic function. Named after the most famous of Victorian prison administrators, it divides the homes of the respectable and law-abiding residents of suburbia from the refuse tip in which the vermin who offend against the law and their mores are exiled and immured. That refuse tip, or ‘penal dustbin’ as it was described by one of its own governors, is Her Majesty's Prison Wormwood Scrubs. With its massive walls and fortress gates embossed with the faces of those great penal reformers John Howard and Elizabeth Fry, it is an enduring and intimidating reminder of the Victorians’ moral certainty and of their indomitable determination to enforce the law and to punish, deter and reform the criminal. The great surviving castellated institutions of incarceration – or their modern monolithic equivalents – that stand like citadels in our major cities or outside our county towns, or are clustered on islands or dotted throughout some parts of our countryside, appear so monumental in design and so intrinsic to the criminal justice system that it is tempting to think of them as permanent and fixed features of the British legal landscape, immemorial, immutable, immovable. Punishment and imprisonment are almost synonyms.