In World War I, the detail and accuracy of maps improved rapidly over the course of a few years and greatly enhanced the power of military forces. Maps, however, were only as good as those interpreting them, and failures in map usage resulted in massive casualties, which ranged from tens to hundreds of thousands. An audience of some seventy persons learned these facts and more about the intersection of cartography and warfare while attending The Maps of World War I. The event held on a May 25th event was sponsored by the Phillips Map Society and coordinated by the Library of Congress, Geography and Map Division.

Ryan Moore, this author, spoke on the topic of The Maps of World War I. He discussed how at the outbreak of war in 1914, maps were scaled too large for tactical planning, meaning only general regions were depicted. Not until 1916 were there highly-detailed maps that indicated individual buildings, bridges, and most importantly, military emplacements and obstacles. Such mapmaking was only possible because aerial reconnaissance planes flew daily sorties and took photographs of the battlefield. The information was transferred to maps and quickly circulated to commanders on the front.

So-called “human intelligence” supplemented the aerial photography; in particular, information harvested from patrols and prisoners was used to populate data on wartime maps.The map below from the American forces is one such example. A notice on the map reads: “Information from captured German maps, prisoner’s statements (sic) and recent aeroplane photographs.” The map notes artillery and machine gun emplacements. Behind the German trench line sits the “Kriemhilde Stellun,” which was a portion of the vast system of defenses in northeastern France known as the Hindenburg Line. The Germans used Russian prisoners to construct the line during the winter of 1916-17. An additional detail from map: “For the last two months men have been working on these trenches; deepening them and building deep dugouts capable of housing fifty to one hundred men each.”

Professor Peter Doyle of the University of London spoke on Terrain, Maps & Failure at the Dardanelles, 1915. He noted that the disastrous British bid to march across Gallipoli with the goal of reaching the Ottoman capital of Constantinople (today Istanbul) failed, in no small part, due to the British reliance on topographical maps that lacked sufficient detail. British intelligence had updated a French map of the Gallipoli peninsula from 1854 at the scale of 1:50,000 to a new version in 1908 at the scale of 1:63,360. These changes made the ground appear less steep and treacherous to the untrained eye. After British troops made a series of amphibious landings, they encountered beaches that were overlooked by high ground filled with Ottoman troops; beyond those points were treacherous cliffs and deep valleys that hindered the offensive. Professor Doyle noted that maps alone, however, were not to blame; it was also the issue of the interpretation (or misinterpretation) of the data.

Following the talks, the public was invited to an open house in the Geography and Map Division, where more than a dozen maps from World War I were available for viewing in the division’s foyer. The display will be remain until the end of July.

If you have any questions about the Phillips Map Society or this event, please contact Ryan Moore at [email protected] or consult the Phillips Map Society website.