A British trench near the Albert-Bapaume road at Ovillers-la-Boisselle, July 1916 during the Battle of the Somme. The men are from A Company, 11th Battalion, The Cheshire Regiment.Photograph Source: Public Domain
The phrase "going over the top" came into usage during World War I and referenced attacking infantry rising out of their own trenches to assault the enemy. In order to attack opposing trench lines, infantry were required to climb over the parapet of their trenches and cross "No Man's Land." As World War I offensives generally sustained heavy losses, "going over the top" was an unpopular activity for soldiers.