The first prisons were in the dungeons of empires and castles, places of neglect and sheer oblivion. Every civilization has had its dissenters and its 'deviants' - criminals as well as political offenders, and so prisons became essential to the retention of power. As the centuries passed after classical times, and prisons were needed for other categories of person, such as debtors, states across the world began to cater for a variety of prisoners,...