Michael Mann is the world’s leading historical and comparative sociologist. After early positions at the University of Essex and the LSE, in 1987 he moved to UCLA, where he has been Professor of Sociology ever since. His work has centred on the dynamics of social power, which he examines in his magisterial four-volume masterpiece The Sources of Social Power. Distinguishing four major sources of power in society – ideological, economic, military and political – this work examines the ways that they have shaped human history from the beginning to the present. Immensely wide-ranging and rigorously analytical, Mann has been described as the Max Weber of our time. Polity has published his concise account of the key concerns that animate his work, Power in the 21st Century (with John A. Hall).