In a penetrating account of the evolution of British intelligence gathering in India, C. A. Bayly shows how networks of Indian spies were recruited by the British to secure military, political and social information about their subjects. He also examines the social and intellectual origins of these ‘native informants’, and considers how the colonial authorities interpreted and often misinterpreted the information they supplied. It was such misunderstandings which ultimately contributed to the failure of the British to anticipate the rebellions of 1857. The author argues, however, that even before this, complex systems of debate and communication were challenging the political and intellectual dominance of the European rulers.