Trench warfare involves combatants attacking one another while maintaining protected positions in elongated earthen ditches. This method of warfare is most widely associated with World War I. The Allies created frontline trenches for attacking the enemy from 50 yards to a mile away and a series of support trenches holding troops and supplies several hundred yards farther back.
Some trenches are deep enough for troops to stand in without being detected, while others permit only crawling. Soldiers typically dig a series of interconnected trenches to provide escape routes and enhance troop mobility. Firing positions feature raised steps on which troops perch to aim their weapons. Boards placed on the muddy floors provide firm footing.
The French military initiated the use of trench warfare in the 17th century. The invention of cannons prompted Civil War troops to dig trenches. Millions of men fought battles in 12,000 miles of trenches in Belgium, France and Switzerland during World War I. The ditches protected them from machine gun fire. Two or more connected trench lines usually ran parallel to one another. They were often made in a zigzag pattern to prevent an intruding soldier from shooting more than a few feet. The trenches contained command posts, supply dumps, first aid stations, kitchens and latrines.