Trench warfare
Trench warfare occurred when a revolution in firepower was not matched by similar advances in mobility, resulting in a grueling form of warfare in which the defender held the advantage. On the Western Front in 1914–1918, both sides constructed elaborate trench, underground, and dugout systems opposing each other along a front, protected from assault by barbed wire, mines, camouflaged trapping pits, and other obstacles. The area between opposing trench lines (known as "no man's land") was fully exposed to artillery fire from both sides. Attacks, even if successful, often sustained severe casualties.
Trench map
These first trench maps, used until the Summer of 1915, also suffered from a lack of standardization. In the absence of a single, theatre-wide format for trench maps, some rather idiosyncratic patterns came into being in these early days of trench warfare. For example, on the British 1st Army Front, troops used the notorious maps that the intelligence officer Col. Charteris favored, which actually printed the North on the bottom and the East on the left-hand side of the map! In addition, the inverted Charteris maps lacked an over-printed grid with hash-marks, so that individual targets required individual target reference numbers. The British Army had to fight two of the largest early battles of the war, those of Aubers Ridge and Festubert, using these wholly unsatisfactory maps.