We explore why the idea of the criminal class came into being. Starting with garrotters lurking in dark Victorian alleyways, the fiend Jack the Ripper stalking London's streets to the menace of violent gangs, the 'Scuttlers', Peaky Blinders, and Liverpool's High Rip, all the way through to 1970s joyriders, 1990s ravers, and the modern drug trade that brings guns and knives to our streets. It describes the actions taken to control the hard-core group - increasingly harsh punishments, executions, floggings, long prison sentences and the ways that society learns about crime, dangerous areas, and the people who habitually offend against society. How do we know what dangers apparently lurk in the inner cities? What part did the newspapers, authors and social investigators play in sensationalising some crimes, and were they right to do so? The book compares real-life criminals (and their lives) with fictional accounts, such as the Artful Dodger, Pinkie in Brighton Rock, and the scenes that social investigators such as Henry Mayhew dragged back from the criminal rookeries to entertain and frighten respectable people. Perhaps most importantly, the book shows which groups have been targeted as the criminal classes, particularly the young, as well as ethnic and racial minorities, and concludes by asking, "Who are the new criminal classes likely to be?"