Behind the enigma: the authorised history of GCHQ, Britain’s secret cyber-intelligence agency

methods from the anti-terrorist campaign in Bengal, such as the use of agents and informers (in ports and on board ships) in an effort to penetrate the subaltern world of maritime smuggling’ (p. 266). Expanding the framework, Silvestri explains how police and civil servants used the expertise they gained against revolutionaries in Bengal to intelligence and insurgency in the British Caribbean, Ireland, London, North America, Palestine and Southeast Asia. He reviews lives of specific intelligence officers after working in Bengal and finds they continued their careers in new locations, taking their knowledge of ‘surveillance, information-gathering, and intelligence analysis’ that was ‘blended with paramilitary policing, coercive interrogation, and collective punishment’ to new places (p. 312). In the epilogue, Silvestri continues with this theme and briefly examines Bengal intelligence officers during the Second World War to demonstrate their contribution to the wartime effort. Silvestri successfully traces the development of imperial intelligence in Bengal, highlighting the nature of imperial power, the brutality of maintaining that power and intelligence’s global reach. He describes the mundane tasks of police intelligence in Bengal, but also the intricate transnational complexity of imperial intelligence in how colonial officers reacted to Bengali revolutionaries’ activities in India and beyond. One important aspect of intelligence and policing from this era not analysed was fingerprinting in Bengal (Silvestri briefly mentioned fingerprinting in one sentence on page 94). The role of colonialism and police in fingerprinting is notable as it was developed in Bengal during this period as a way for colonial authorities to distinguish between people who could not write their ‘names and are otherwise hardly distinguishable by Europeans.’ Nonetheless, the level of research was impressive with Silvestri drawing from contemporaneous first-hand accounts, newspapers and a large body of archival material from India, the United Kingdom and the United States. This highly recommended study will be useful to readers interested in colonial intelligence, terrorism and political violence, and South Asian history.