Michael Dobbs, the author of this novel, states in an after note, “the world will never know the full debt of gratitude it owes to Winston Spencer Churchill”.

Germany has just completed its conquest of Denmark and Norway and has turned its attack to the west by invading France, Belgium, the Netherlands and Luxembourg.

Within days of his taking office, the Low Countries have been overrun and the mighty French army is crumbling to crushing defeat in the face of Germany’s blitzkrieg.

The British Expeditionary Force, transported to the continent during the months of “Phoney War”, have been cut off from their French allies and are scattered and stranded along the Channel coastline.

Pummelled by the German Luftwaffe air superiority and pounded by the Wehrmacht’s Panzers, it faces total annihilation.