World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a global conflict between two coalitions: the Allies and the Central Powers. Fighting took place mainly in Europe and the Middle East, as well as in parts of Africa and the Asia-Pacific. In Europe it was characterized by trench warfare; the widespread use of artillery, machine guns, and chemical weapons (gas); and the introductions of tanks and aircraft. World War I was one of the deadliest conflicts in history.