Elvire De Greef, (born June 29, 1897, Ixelles, Belgium, d. August 20, 1991, Brussels), code name Tante Go or Auntie Go, was a member of the Comet Escape Line in World War II.

In May 1940, when the German army invaded and occupied Belgium, the De Greef family and an Englishman named Albert Edward Johnson fled in an attempt to transit Spain and take refuge in the United Kingdom.

As a translator and interpreter for the French with the German army, he had the opportunity to gather intelligence and steal and falsify documents, stamps, and identification cards and was assisted by his son, Frederick.

[2] On Appert's advice, Deppé made contact with the De Greef family and arranged for their help in getting people across the border.

From this experience, de Jongh realized that in future exfiltrations they must accompany their charges secretly all the way to the British Consulate in Bilbao.

Her helpers included the three members of her family, about a dozen other key people who lived in neighboring cities and towns plus a number of sympathizers, and several Basque guides who were paid for leading escapees over the mountains into Spain.

[12][13] The allies put a high priority on recovering airmen shot down in Europe and returning them to service as it was time-consuming and expensive to train replacement aircrew.

[14] One of De Greefs most important helpers was a Basque widow, Kattalin Aguirre, who along with her 14-year-old daughter, Josephine ("Fifine"), provided a safe house for airmen after they got off the train in Saint-Jean-de-Luz and set them on their way toward the nearby border.

[15] Elvire De Greef's daughter, Janine (often spelled Jeanine), was the youngest guide of the Comet Line, first accompanying aviators by train from Paris to Bayonne when she was only 16.

The usual practice of the Comet Line was for airmen and other evacuees to travel by train from Brussels or Paris with an escort, often Andree de Jongh, to either Bayonne or Saint-Jean-de-Luz.

The airmen and their escort were met and conducted to a safe house where they would await favorable conditions for the walk to Spain over the Pyrenees mountains which reached elevations of only about 700 metres (2,300 ft) in this region.

During the first year of operation, the De Greef's home usually hosted the evacuees, but later a network of safe houses was established.

From Urrugne it was a one to three night hike of about 25 kilometres (16 mi) with a Basque guide, usually one who had been a smuggler and knew the mountains intimately, across the Franco-Spanish border to Oiartzun, near San Sebastián.

In December 1943, Comet Line leader Antoine d'Ursel and American pilot James F. Burch were drowned while attempting to cross the river.

[21] Several Basque guides worked with the Comet Line, the most competent being Florentino Goikoetxea, a smuggler and a fugitive from Franco's Fascist government, who could find his way across the Pyrenees at night without difficulty.

On June 6, 1944 with the German Gestapo closing in on the De Greef's and their organization, Elvire and her son and daughter crossed the border into Spain.

Returning from a mission on July 26, he was shot four times by German border guards although he managed to hide the documents he was carrying.