"Hundred Days Offensive"—kicked off on August 8, 1918, with a decisive victory at Amiens, France—against the Hindenburg Line in late September.
Australian, British, French and American forces participated in the attack on the line, which began with the marathon bombardment, using 1,637 guns along a 10,000-yard-long front. In the last 24 hours the British artillery fired a record 945,052 shells.
After capturing the St. Quentin Canal with a creeping barrage of fire—126 shells for each 500 yards of German trench over an eight-hour period—the Allies were able to successfully breach the Hindenburg Line on September 29.
The offensive was driven ahead by Australian and U.S. troops, who attacked the heavily fortified town of Bellicourt with tank, aircraft and artillery support. After four days of battle, with heavy losses on both sides, the Germans were forced to retreat.
With Kaiser Wilhelm II pressured by the military into accepting governmental reform and Germany’s ally, Bulgaria, suing for an armistice by the end of September, the Central Powers were in disarray on the battlefield as well as the home front. The Allies, meanwhile, pressed their advantage on the Western Front throughout the following month, which would, against their predictions, turn out to be the final month of World War I.