They say each generation needs its own biographies of Cleopatra, Joan of Arc and Napoleon, not just when more evidence is unearthed but because the lens through which we view character and motive changes. The same is true for the great set pieces of history.

According to Ben Macintyre, the story of Colditz and its second world war POWs with their ‘moustaches firmly set on stiff upper lips, defying the Nazis by tunnelling out of a grim Gothic castle on a German hilltop’ has been unchanged and unchallenged for more than 70 years.