The crucial part played by intelligence and espionage techniques - by spying - in Britain during the Civil Wars and the Commonwealth has rarely been studied, yet it is a key to understanding the dangerous politics and the open warfare of those troubled times. In this fascinating and original account, Julian Whitehead traces the rapid development of intelligence techniques during this, one of the most confused and uncertain phases of British history. His vivid narrative demonstrates how leaders on all sides set up increasingly effective systems for gathering and interpreting intelligence, and it shows the decisive impact intelligence had on events. The intrigue, the secret operations, the many plots and counter-plots, and the colourful personalities involved, make compelling reading.