One of the world's greatest political scandals of the 20th Century was the revelation that KGB spies had infiltrated UK intelligence. The 4 most notorious were (from left to right): Anthony Blunt (a cousin of Queen Elizabeth the Queen Mother), Donald Maclean, Guy Burgess and Harold "Kim" Philby, the UK intelligence operative (later, KGB colonel) who helped to establish the CIA when he was based at the British Embassy in Washington D.C. in the late 1940s.
Stalin's Englishman: The Lives of Guy Burgess by Andrew Lownie. Guy Burgess was the most important, complex and fascinating of 'The Cambridge Spies' - Maclean, Philby, Blunt - all brilliant young men recruited in the 1930s to betray their country to the Soviet Union. An engaging and charming companion to many, an unappealing, utterly ruthless manipulator to others. http://www.andrewlownie.co.uk/authors/andrew-lownie/books/stalins-englishman-the-lives-of-guy-burgess