British troops in World War I British troops in a trench on the Western Front during World War I. Encyclopædia Britannica, Inc. The typical trench system in World War I consisted of a series of two, three, four, or more trench lines running parallel to each other and being at least 1 mile (1.6 km) in depth. read more
During trench warfare, opposing armies conduct battle, at a relatively close range, from a series of ditches dug into the ground. Trench warfare becomes necessary when two armies face a stalemate, with neither side able to advance and overtake the other. read more
1. Trench warfare was used extensively on the Western Front by both sides, after the Battle of the Marne in 1914. 2. At its core, trench warfare was a form of defensive warfare intended to halt enemy assaults and advances. 3. Trench systems were extensive and complex, intended to hinder an enemy assault while allowing for fallback positions. 4. read more