World War I: First tank-to-tank combat, during the second Battle of Villers-Bretonneux. Three British Mark IVs meet three German A7Vs.

World War I, or the First World War, also known as the Great War, was a global conflict between two coalitions: the Allies and the Central Powers. Major theatres of war included Europe and the Middle East, and well as parts of Africa and the Asia-Pacific. One of the deadliest conflicts in history,…