Historians believe Allied bombardments killed almost as many French people as German bombs killed Britons during the Blitz.
According to research carried out by Andrew Knapp, history professor at the UK's University of Reading, British, American and Canadian air raids resulted in 57,000 French civilian losses in World War Two.
"That's a figure slightly below, but comparable to, the 60,500 the British lost as a result of Luftwaffe bombing over the same period," says Knapp who is the co-author of Forgotten Blitzes and a book just published in France called Les francais sous les bombes alliees 1940-1945 (The French Under Allied Bombardment).
"It is also true that France took seven times the tonnage of [Allied] bombs that the UK took [from National Socialist Germany]," says Knapp. "Roughly 75,000 tonnes of bombs were dropped on the UK [including Hitler's V missiles]. In France, it's in the order of 518,000 tonnes," he says.
Winston Churchill, who addressed the French over the airwaves with confidence and even a certain relish in their own language, spoke to them as Allies despite the collaboration with the Nazis of a part of the French population.
But the bombing tactics employed did not always reflect this.
Knapp divides the Allied bombardments into three categories: "Some did manage to be accurate and cause minimal civilian casualties.
"The second category, you can see why they did it but the level of civilian casualties might be considered disproportionate to the military advantage. And the third category it's really quite hard to understand, even with hindsight, why they did it at all."
The most disturbing example is the bombing of Le Havre in September 1944. Nearly all of the city was reduced to ash and 5,000 French men, women and children were killed. Allied infantry took the port a few days later but, many believe, they would have done it without the bombardment.
"It's fairly clear," says Knapp, "that on the basis of the treaties we have signed now - not the treaties we had signed then - some of these raids would be eligible for the category of war crimes."
Catherine Monfajon, author of a documentary on the subject that has just been shown on French TV, says the French often showed great spirit.
At the funeral for more than 100 French apprentices killed in an Allied air raid on St Nazaire, when a Vichy official started speaking about "birds of death", a whistle of disapproval rose from the very gallery where the parents of the dead boys were standing.
At the end of the War, St Nazaire was recorded as "100% destroyed" but talking about the destruction in this and 1,500 other towns was taboo.
"That silence is amazing and amazed me," says Monfajon. "France was the third country most bombed by the Allies after Germany and Japan and it is hardly mentioned in our history books."
This was largely because of the way the collaborationist Vichy regime used these casualties in their propaganda in order to turn public opinion against the Allies.
Even so much as questioning the bombing was considered suspect, she says. "And people were split between their pain, their anger and their gratitude towards these pilots who brought them freedom. Who died for that."
Rubble and ash
As the bombing of French cities intensified around D-Day, Churchill expressed concern that the scale of civilian casualties could durably damage Anglo-French relations even after the war was won.
Arthur "Bomber" Harris, head of RAF Bomber Command, wanted all his bombers pounding Germany.
Although apparently untroubled by the carnage inflicted on German civilians, he was pained by French casualties to the point of collecting money to send to help Allied bombing orphans.
Almost half of Bomber Command's airmen were killed in action. Their missions, their commanders argued, would help win the war more quickly.
But as the French are finally daring to say, the "liberation" of Normandy towns like Saint Lo, Caen and Le Havre turned them into wastelands of rubble and ash.
On D-Day itself, 2,500 Allied soldiers were killed. About the same number of French civilians were killed also.