The Battle of Flanders marked the conclusion of the war of movement or fighting in the open on the Western Front.
From the end of 1914 until nearly the end of the war in 1918, the fighting consisted largely of trench warfare, where each side laid siege to the other's system of trenches. They consisted of numerous parallel lines of intercommunicating trenches protected by lines of barbed wire.
Both sides established lines extending about 500 miles from Switzerland to the North Sea.
These lines were to remain almost stationary for the next three years. The western part of the Allied line was held by the British who, in the race for the channel, had advanced to Ypres, the southwest corner of Belgium. In December the Allies attacked along the entire front, from Nieuport in the west to Verdun in the east, but failed to make any appreciable gains. By this time operations on the Western Front had resulted in nearly one million Allied casualties; German losses were almost as great.