What we now call trench maps are an organized set of maps at a detailed scale which start on the coast either side of the French and Belgian border and go, numerically, in a north-west to south-east flow down through France and Belgium. Using pre-war French and Belgian maps as a reference these maps show an idealized landscape long since fought over and largely destroyed. Overlaying the topographical information are the trenches of of both the British and German armies, facing each other of what was often a very narrow strip of no-man’s land. German trenches were shown in full while almost always only the front-line of the British trenches would be included for security reasons*.

Fonquevillers, 57D N.E., sheets 1 & 2 (parts of) Feb 1917 C1 (3) [1449]
This map has the village of Monchy au Bois at the top, and is dated to a time between the Battles of the Somme and Arras, with ‘trenches corrected to 27-12-16’, and this sheet is edition 4a. In total there were ten different editions of this sheet made between September 1915 and November 1916, a demand on map production made possible by the Ordnance Survey providing mobile printing presses behind the front-line. The maps show an ordered topographic representation of a pre-war landscape, with villages laid out, streets, churches and countryside. In reality the village would be a ruin, as can be seen in this image from the Imperial War Museum (Image: IWM (Q 61260) of the village in June 1917

The main purpose of the maps was to give artillery positions behind the lines accurate co-ordinates for firing on enemy positions, often from information given to them by forward observation posts. Maps would be gridded, areas separated into smaller areas by a designated letter, then each square within the lettered area numbered. These squares were then divided by a broken line into 4, a,b,c and d. Finally, to give as accurate a reference as possible, ‘tick lines’ are included around the edge of the square, 10 on each line. Using this system would give a simple but highly accurate point of reference for artillery to work on.


This is how most trench maps work. Occasionally though an extra help to identify location was given on a map. Key positions would be numbered in red circles. These positions would be at junctions or corners of trenches, areas where troop movements would slow down and soldiers would inevitably bunch up. In a calculated way artillery fire would be targeting areas which would give the maximum casualties amongst enemy forces for the minimum shell use. These are extracts from the trench map showing the grid system in place and then the circled numbers at the points of junctions.
*Here’s an example of a trench map with both British and German trenches, La Bassėe, sheet 44a N.W. 1, 1918. With the extra trenches these maps become more than just an historical record of the course of a battle at a particular time. With named trenches they are part of the social history of the First World War as well.
























































