Secret wartime documents have revealed how Allied code breakers uncovered a Nazi plot to steal the Bayeux Tapestry to hang on the walls of Heinrich Himmler's castle.
Hitler's deputy sent a coded signal to SS chiefs in Paris ordering the masterpiece be taken back to Berlin before Paris was reduced to rubble on the Fuhrer's orders.
But Bletchley Park intercepted the signal from the dreaded Gestapo chief and ensured the French Resistance got to the Louvre first with just 48 hours to spare.
Four SS goons arrived with two trucks and enough spare fuel to get back to Germany but were sent packing by a hail of bullets from the partisans.
The plans to steal the Bayeux Tapestry have been revealed for the first time
The fragile strip of embroidered linen was found safe in a crate in the basement when Paris was liberated just days later.
A long-lost file found in the National Archives has revealed Bletchley Park was intercepting messages to police stations and SS barracks even before war broke out.
The "police section" amassed thousands of intercepts of police units on the eastern front, and police headquarters in Germany
The code-breakers opened the dossier on the Nazi looting operation after learning about it in police decodes sent from Russia in the closing months of 1942.
Hitler's deputy wanted the tapestry to hang on the walls of his castle
A Military Intelligence officer wrote: "The work of plundering is carried out by a special battalion of the SS commanded from Berlin.
"One of the Battalion's officers captured in the Northern Caucasus admitted that in the German Army regular plundering detachments were formed.
"Their task was to rob churches, museums, picture galleries etc and bring their booty to Germany.
"The Czar's palaces near Leningrad were robbed of valuable documents, artistic treasures and furniture.
Himmler's plot was uncovered by UK code breakers
"These prizes were reserved for the use of the higher Nazi bosses in their villas. The lesser bosses had to content themselves with rare books and costly vases."
Initially, the Allies built up a file on Nazi looting purely for propaganda purposes to discredit Hitler and his cronies.
But all that changed at 12.35pm on August 18 1944, when Himmler sent Carl Oberg, head of the SS in France, an urgent radio message decrypted by Hut Six at Bletchley.
Translation staff in Hut Three were stunned to see the order read "Do not forget to bring the Bayeux Tapestry to a place of safety" and ` knowing that meant the heart of the Reich - called the duty officer.
The tapestry was taken off display and packed away by the French
As Hitler's armies marched into Poland, the Bayeux Tapestry had been taken off display by the French and packed into a zinc lined crate, wrapped in sheets and liberally sprinkled with moth powder.
After France fell, a special "research" of the SS was set up by Himmler to establish the Tapestry's credentials as an Aryan art work - as the Normans were descended from the Vikings.
Himmler had reserved a space to hang the tapestry in his own renovated medieval castle in Westphalia.
As the Allies closed in on Paris, Himmler ordered the SS to collect his prize, which was by then hidden in the cellars of the Louvre.
But because the message was intercepted, the French Resistance were able to occupy the museum before Himmler's thugs turned up to carry out his orders two days later.
In November 1945, the Tapestry was put on show at the Louvre, to coincide with Churchill's visit to Paris, before being returned to Bayeux where it is now lovingly preserved in a purpose-built exhibition centre.