Power on the Inside is the first book to examine the historical development of prison gangs worldwide, from those that emerged inside mid-nineteenth-century Neapolitan prisons to the new generation of younger inmates challenging the status quo within gang subcultures today. Historian-criminologist Mitchel P. Roth examines prison gangs throughout the world, from the Americas, Oceania, and South Africa to Southeast Asia, Europe, and beyond. The book examines the many variables that influence the evolution of prison subcultures, from colonialism and population demographics to prison architecture and staff-prisoner relations. Power on the Inside features eighty historical and contemporary images and will inform professionals in the field as well as general readers who want to know more about the realities of prison gangs today.