Also called "The Paris Gun" and "Large Max" and named in honour of the German leader Wilhelm II, it is often confused with Big Bertha, the howitzer used by the Germans against the Liège forts in 1914, and indeed the French called it by this name as well.
The German objective was for a psychological weapon to attack the morale of the Parisians; not to destroy the city itself.
The gun was designed by Professor Rausenberger for Krupp. The weapon had a 210mm calibre, with a 45m-long barrel braced along its length to prevent muzzle droop, it weighed 256 tons. It used 200kg of propellant to project[?] the 120kg projectile on its 170 seconds and 120 km trajectory to Paris.
The gun was fired from the Forest of Coucy and the first shell landed at 7.18 a.m. on March 21, 1918. Only when sufficient shell fragments had been collected was it realized that the explosion had come from a shell.
A total of 367 shells were fired, killing 250 people and wounding 620, as well as causing considerable damage to property.
The gun was taken back to Germany in August 1918 as Allied advances threatened its security. The gun was never seen by the Allies; towards the end of the war it was completely destroyed by the Germans. Because of this the figures stated for the weapon's size, range and performance vary widely depending on the source - not even the number of shells fired is certain.