The Battle of the Marne took place in France during WWI from September 5-12, 1914. In the summer of 1914, the Allied troops were in full retreat. Nothing seemed to be able to stop the powerful German offensive. What could save France from an imminent disaster? On September 2nd, a massive counter-attack was in progress along the Marne River. On September 5th, the Allied engaged the enemy.
History books speak of the "Miracle of the Marne," describing the superhuman effort of an exhausted army. There is no question about its astonishing character, but the "rational" explanation is not incompatible with a divine intervention, giving another meaning to the expression "Miracle of the Marne." Among the many witnesses of the Blessed Virgin’s presence in this decisive battle, we have the testimony of Mrs. Tripet-Nizery, who was a war nurse in 1914-1916. A German officer prisoner-of-war had confided to her: "You were surprised that we left suddenly just after we arrived at the gates of Paris. We could not go any further, because a virgin blocked the way. We didn’t know if it was one of your national saints, Genevieve or Joan of Arc. Afterwards, we understood that it was the Blessed Virgin, who paralyzed us on the spot."
Source: Marne