Aerial reconnaissance played a significant role 100 years ago in the unfolding of the First Battle of the Marne. Louis C. Breguet of the famous watch-making family, who was also a budding aircraft designer, had himself assigned as an enlisted pilot. Flying a Breguet AG-4 of his own design and manufacture on 2 September 1914, he spotted the German forces changing direction, moving from west to east rather than trying to circle around Paris. He informed his headquarters of it. Getting the generals to act on this information was a tougher task, however.
|An AG-4 of the Type Used by Breuget in His Mission|
The next day the Royal Flying Corps substantiated Breguet with its own report that "disclos[ed] the movements of all the Corps of the I German Army diagonally South East across the map toward the Marne." Alarmed by these reports and the lack of response from senior officers, Capitaine Georges Bellenger, commander of the air unit supporting the Sixth Army being formed in Paris, appealed to General Gallieni, commander of the Paris District. Won over, Gallieni then made the case to supreme commander Joffre that the Germans were exposing their flank to an attack out of Paris.
The net result of this collaborative effort was that over a period of three days the Germans marched into a salient with the French 5th Army on their left flank, the French 6th Army on their right flank, and the British Expeditionary Force standing firm at the bottom of the pocket.
Sources: Walter J. Boyne, "The Influence of Airpower on the Marne," Air Force Magazine, July 2011; Shooting the Front, Terrence Finnegan, 2006.