Bernard Porter 
Plots and Paranoia [PDF ebook] 
A History of Political Espionage in Britain 1790-1988

Britain’s secret state exists to protect her from ‘enemies within’. It has always aroused controversy; on the one hand it is credited with preventing wars, revolutions and terrorism and on the other it is accused of subverting democratically elected governments and luring innocents to death. What is the true story? The book, first published in 1992, delves beneath the myths and deceptions surrounding the secret service to reveal the true nature and significance of covert political policing in Britain, from the ‘spies and bloodites’ of the eighteenth century to today’s MI5. This title will be of interest to students of modern history and politics.