According to different scholars, the history of anarchism either goes back to ancient and prehistoric ideologies and social structures, or begins in the 19th century as a formal movement. As scholars and anarchist philosophers have held a range of views on what anarchism means, it is difficult to outline its history unambiguously. Some feel anarchism is a distinct, well-defined movement stemming from 19th-century class conflict, while others identify anarchist traits long before the earliest civilisations existed.
Prehistoric society existed without formal hierarchies, which some anthropologists have described as similar to anarchism. The first traces of formal anarchist thought can be found in ancient Greece and China, where numerous philosophers questioned the necessity of the state and declared the moral right of the individual to live free from coercion. During the Middle Ages, some religious sects espoused libertarian thought, and the Age of Enlightenment, and the attendant rise of rationalism and science, signalled the birth of the modern anarchist movement.