When do countries democratize? What facilitates the survival of authoritarian regimes? What determines the occurrence of revolutions, often leading to left-wing dictatorships, such as the Soviet regime? Although a large literature has developed since Aristotle through contemporary political science to answer these questions, we still lack a convincing understanding of the process of political development. Employing analytical tools borrowed from game theory, Carles Boix offers a complete theory of political transitions, in which political regimes ultimately hinge on the nature of economic assets, their distribution among individuals, and the balance of power among different social groups. Backed up by detailed historical work and extensive statistical analysis that goes back to the mid-nineteenth century, this book explains why democracy emerged in classical Athens. It also discusses the early triumph of democracy in both nineteenth-century agrarian Norway, Switzerland and northeastern America and the failure in countries with a powerful landowning class.