The Cambridge Five - Donald Maclean, Guy Burgess, Kim Philby, John Cairncross and Keeper of the Queen's Pictures Anthony Blunt - made up one of the most notorious spy rings of the 20th century. Besotted with communist ideology and radicalised while at Cambridge University in the 1930s, their clandestine supply of British and US intelligence material gave Stalin an inside track on US and British decision-making until May 1951.

So how did this collective come into being, what brought about its downfall, and why did four of the five never answer for their crimes?

In this episode, Antonia Senior draws on recently declassified files to reexamine the story of the Cambridge Five. Discussing her new book Stalin’s Apostles: The Cambridge Five and the Making of the Soviet Empire with historian and philosopher Sophie Scott Brown, Senior explores how a generation shaped by the crises of the 1930s was drawn to communism, and how elite networks within Cambridge and the British establishment enabled one of the most damaging intelligence breaches in modern history.

Antonia Senior is a journalist and writer. She is the author of Stalin’s Apostles: The Cambridge Five and the Making of the Soviet Empire.

Sophie Scott Brown is a historian and philosopher specialising in modern intellectual history and political thought.