I Was Monty's Double

A few months before the Normandy landings during the Second World War, the British government decides to launch a campaign of disinformation; spreading a rumour that the landings just might take place at a location other than Normandy. The details of the operation (actually, there were several such operations) are handed to two intelligence officers, Colonel Logan (Cecil Parker) and Major Harvey (John Mills). They are initially unable to devise such a plan – but one night, Harvey sees an actor at a London theatre, putting on a convincing impression of General Bernard Law Montgomery, 1st Viscount Montgomery of Alamein.