May 23, 1940.

“Nothing but a miracle can save the BEF [British Expeditionary Force] now, and the end cannot be very far off,” General Alan Brooke, Commander of II Corps.

Astonishingly, that very evening, the Panzers shut their engines.

The Dunkirk saga had begun.

Christopher Nolan’s masterpiece Dunkirk highlights the troop evacuation that allowed Britain to remain in the war.

But that’s only half of the story.

The other half, the German half, is equally intensive but far more confusing.  Why did the Panzers stop? Who gave the halt order? Why did the Luftwaffe fail to flatten the massed troops at the beaches?

But before we unravel the riddle and try to answer these questions, a short course on German military hierarchy is essential.