Calder Walton is a leading expert among a new generation of intelligence historians. He has published widely on intelligence history and contributed to a number of books on British foreign policy and international relations. While completing a PhD in history at Trinity College, Cambridge, and then a post-doctoral Fellowship at Darwin College, Cambridge, he was one of the principal researchers on Christopher Andrew's unprecedented authorised history of MI5. He lives in London, where he works as a barrister. This is his first book.