Anarchism refers to a tradition of social and political thought that in the 1860s emerged as an organized political force. Since then, anarchism has inspired protests, organizations and movements, mainly in Europe, Russia and the Americas, but also in other parts of the world. While it may be difficult to talk of ‘one’ anarchist movement, a distinct anarchist current within the history of the labor movement can be identified as well as anarchist tendencies and groups within other social movements. The term ‘anarchy’ comes from the Greek an-arkhos, meaning ‘without a leader or ruler’. It was first used in a positive sense, being identified as the ideal form of government, in Pierre- Joseph Proudhon’s (1809-1865) What Is Property? (1840). Proudhon, Mikhail Bakunin (1814-1876) and Pyotr Kropotkin (1842-1921) pioneered a broad tradition which has developed in a variety of forms. These range from varying interpretations of how to organize society in economic terms to the more basic distinction between social anarchism and currents farther removed from collective action (e.g. philosophical, individualist, and spiritual anarchism) as well as more specific variations around forms of organization, of action, the use of violence, and so on. In spite of this rich variety, anarchism can be identified by its strong commitment to individual freedom and sovereignty, the opposition to any form of oppression, domination and authority, the promotion of voluntary, decentralized and non-hierarchical associations, and the use of forms of direct action that prefigure a freer society with more solidarity and respect for individual self government.