A trench in Battle of the Somme, July 1916

Trench warfare is a war tactic, or way of fighting. It was commonly used on the Western Front in the First World War. It has also been used in other wars, like the Iran-Iraq War.

In trench warfare, the two sides fighting each other dug trenches in a battlefield. These trenches had many different parts, such as places for sleeping, for headquarters, for storage, and for artillery and machine guns. Between the front trenches, on the battlefield, was an area called "no man's land". This area was often covered with barbed wire and land mines. Soldiers on each side would try to cross no man's land to get to the enemy's trench and attack. Tanks were commonly used to cross this land.