This book is about the principle of proportionality--the principle that a sentence should be proportionate to the seriousness of the offense committed. Although the principle has often been discussed, this book breaks new ground by examining more fully the detailed arguments for the theory and for applying it to a range of situations including young offenders, dangerous offenders and socially deprived offenders. The authors are well known for their previous writings on proportionality theory, and this book broadens the theory to deal with important contemporary issues in crime and punishment.