The conflict characterized by trench warfare and significant loss of life was World War I, which lasted from 1914 to 1918. This war saw the combatants, primarily in Europe, engage in a grueling and static form of warfare, with soldiers fighting from trenches dug into the ground. The trenches provided some protection but also led to horrendous living conditions and the spread of disease. Battles such as those at the Somme and Verdun resulted in massive casualties, with little territorial gain. The use of advanced weaponry, including machine guns and poison gas, exacerbated the devastation. World War I fundamentally changed the geopolitical landscape and set the stage for future conflicts, leaving a profound impact on 20th-century history.