The term "First World War" came into use on or close to 3 September 1939. That is to say, as soon as the Second World War started. Until then it had been referred to as The Great War
The term "World War" (Weltkrieg) first appeared in Germany in 1914. The French and British referred to the war as "La Grande Guerre" or the "Great War", but also adopted the term "World War" later in the conflict.
