Revolutions have been a part of politics for centuries. Their ideologies, their leaders, and their successes or failures have shaped the history of nations worldwide. This broad comparative survey focuses on five big case studies, beginning with the English Revolutions in the seventeenth century, and continuing with the Mexican, Russian, Vietnamese and Iranian Revolutions. Revolutions in World History traces the origins, developments, and outcomes of these revolutions, providing an understanding of the revolutionary tradition in a global context. The study raises questions about motivations and ideologies. In particular, it examines the effectiveness of these revolutions — and revolution as a concept — in bringing about lasting political changes.