In January 1944 the Germans believed that the Allies were preparing the great invasion of occupied Europe and asked Garbo for information.
Thus began his best work, which would change the course of the war.
The Germans were right: the allies prepared the great invasion. Its code name was Operation Overlord and it was already underway.
But the Germans did not know a fundamental part of that plan. A great deception, in which Garbo would play a fundamental role, Operation Fortitude.
From January until June 6, 1944 – on D-Day when the landing in Normandy began – Garbo sent more than five hundred radio messages.
No less than four transmissions per day.
These messages were relayed directly to Germany and not only concealed the true state of the preparations, but also had another very important objective: to make the Germans believe that the landing would be where Hitler had always believed it would be, in the Calais Pass, much further north than where it was really going to occur.
General Patton and his ghost army
A fundamental part of the deception was the creation of an army that never existed, the First Group of the United States Army (FUSAG), composed of 150,000 men under the command of General George S. Patton, recognized as one of the best tank commanders of the allies.
The imaginary FUSAG was apparently prepared in Kent and Essex ready to join the operation, far from the real invasion force that was concentrated to the west.
With Garbo’s help, the Germans believed that this information was absolutely true.
Announcing the invasion
The operation was so bold that, to get the Germans to believe that the landing in Normandy was nothing more than a distraction maneuver, on June 5 Garbo warned them that they would receive an urgent message after three o’clock.
He hoped to inform them that everything indicated that the troops were about to embark for France. That is, he was going to announce the landing before it occurred.
However, that morning there was no one in Madrid to receive the message and thus the Germans received the information the next day, when the landing had already been made.
For the Nazis, this showed that the information provided by Garbo was reliable and he showed his anger by saying:
I am very disgusted in this struggle for life and death, I cannot accept excuses or negligence. I cannot swallow the idea of endangering the service without any benefit. Were it not for my ideals and faith I would abandon this work as having proved myself a failure.
On June 9, 1944, Day D + 3, Garbo sent what was probably the most important message of his acting as a double agent.
It was very long and requested that it be transmitted urgently to the German High Command. He reported that the First Group of the US Army under Patton’s command had not moved from the southeast of England and that the landing in Normandy was a distraction maneuver to ensure the success of the next assault on the Calais Pass.
The Germans accepted this statement, thus fulfilling the objective of Operation Fortitude.
To such an extent they trusted Garbo’s information that during July and August they maintained two armoured divisions and nineteen infantry divisions in the Calais Pass in anticipation of an invasion.
This gave the Allies precious time to establish their bridgehead and, as British intelligence asserts, Garbo’s intervention in the battle of Normandy really tipped the scales in his favour in World War II.