This article aims to provide an overview of changes in the prison population and of prison population flow policies. For this purpose, a diachronic comparison was used to analyse data and policies regarding Italian prisons from immediately after the Second World War to the present day, revealing that the situation of chronic overcrowding that currently afflicts Italy’s prisons is the result of a concatenation of causes, featuring moments of continuity and others of change with regard to the past. The article then makes certain observations about the causes and effects of the rise in the number of prisoners, stressing that the correlation between the persistent situation of overcrowding and the action of the state is symptomatic of an albeit limited change in practices of handing down prison sentences, which in turn reflects a change in forms of governing urban spaces. Lastly, the article highlights certain elements that set the parameters of the current practice of handing down prison sentences in a phase of gradual expansion of the mechanisms of penal control, underlining how the situation of emergency suffered by Italy’s prisons is determined not only by specific laws, as has been asserted all too often until now, but also by changes in the management policies of the prison system and of its population flows. The article intends to highlight the strategies applied by successive governments to tackle what has proved to be a real prison emergency
Keywords: Overcrowding - Prison - Prison policies - Marginality - Social changes