In almost any piece of film you'll see of Britain's great wartime leader, this is the man in the background - anonymous and secret. Until now his critical role in saving the life of Churchill from a series of attacks has been hidden from the wider public.

After the war Thompson's censored book told just part of the story. His full memoirs were suppressed even by Churchill himself - only now can we recount the number of assassination attempts on Churchill's life.This series, with unique access to these incredible memoirs, reveals the story of Walter's life with Winston. Together they travelled thousands of miles on precarious journeys to meet Stalin and Roosevelt and other world leaders.

This is a story of Churchill's constant brushes with death and the role played by an ex post office messenger in preventing an early end to his life.

This is the full series (13 episodes). You can download individual episodes by clicking on the link below.