Trench warfare is a type of land warfare using occupied fighting lines largely comprising military trenches, in which troops are well-protected from the enemy's small arms fire and are substantially sheltered from artillery.
Trench warfare was started by the Germans in The First World War.
There was 2,490 kilometres of trench lines dug during the First World War.
Most trenches were between 1-2 metres wide and 3 metres deep.
It is estimated that if all the trenches built along the western front were laid end-to-end they would total over 25,000 miles long. The trenches needed constant repair or they would erode from the weather and from enemy bombs.
Trenches provided protection from bullets and shells, but they did carry their own risks. Trench foot, trench fever, dysentery, and cholera could inflict casualties as readily as any enemy.
