The artillery of World War I, improved over that used in previous wars, influenced the tactics, operations, and strategies that were used by the belligerents. This led to trench warfare and encouraged efforts to break the resulting stalemate at the front. World War I raised artillery to a new level of importance on the battlefield.
The First World War saw many developments in artillery warfare. Artillery could now fire the new high explosive shells, and throw them farther and at a higher rate of fire. Because of this, enemies in trenches were no longer always safe, and could constantly be fired upon. In some areas, artillery concentration was common, with several guns firing onto an area such as a line of trenches, each gun firing several rounds per minute for hours. Artillery barrages were also used to divert the enemy's attention from the site of attack before a battle. Paths behind the lines were also fired on so that enemy reinforcements could not safely reach the front lines.[1]
Mortars were revived by the Germans because of their ability to shoot at an angle above 45 degrees, and they, therefore, could theoretically (although not often) drop shells directly in an enemy's trench before exploding, for maximum damage.[2] Artillery shells were used for chemical weapon emission by the German troops in 1915, and the Allies followed their example after the Second Battle of Ypres.