The Paris Gun (German: Paris-Geschütz / Pariser Kanone) was the name given to a type of German long-range siege gun, several of which were used to bombard Paris during World War I. They were in service from March to August 1918. When the guns were first employed, Parisians believed they had been bombed by a high-altitude Zeppelin, as the sound of neither an aeroplane nor a gun could be heard. They were the largest pieces of artillery used during the war by barrel length, and qualify under the (later) formal definition of large-calibre artillery.