Trench warfare is a type of land warfare using occupied lines largely comprising military trenches, in which combatants are well-protected from the enemy's small arms fire and are substantially sheltered from artillery. It became archetypically associated with World War I (1914–1918), when the Race to the Sea rapidly expanded trench use on the Western Front starting in September 1914.
British (upper) and German (lower) frontline trenches, 1916
German soldiers of the 11th Reserve Hussar Regiment fighting from a trench, on the Western Front, 1916
Plan of Ruapekapeka Pā, an elaborate and heavily fortified Ngāpuhi innovation, which James Belich has argued laid the groundwork for or essentially invented modern trench warfare.
Trenches at the Siege of Vicksburg 1863
A trench is a type of excavation or depression in the ground that is generally deeper than it is wide, and narrow compared with its length.
A gas main being laid in a trench
Depiction of the topography of the Puerto Rico Trench, the deepest part of the Atlantic Ocean
Automated trench digging on a street in Baku
Allied troops entrenched in the Battle of Tuyutí.