The Hundred Days Offensive was a series of offensives launched against the Central Powers on the Western Front from August 8 to November 11, 1918, beginning with the Battle of Amiens which was followed by the Grand Offensive. It was the final period of World War I and is sometimes referred to as “Canada’s Hundred Days”, highlighting the prominent participation of the Canadian Corps under British 1st Army command. The offensive led to the final demoralization and withdrawal of the German armies and the end of the Great War.
The German Spring Offensive on the Western Front, which had begun with Operation Michael in March 1918, had ground to a halt by July. Although the Germans had advanced to the Marne River, they had failed to achieve a decisive breakthrough. When Operation Marne-Rheims ended in July, the Allied supreme commander, the French Marshal Ferdinand Foch, ordered a counter-attack which became the Second Battle of the Marne. The Germans, recognizing their untenable position, withdrew from the Marne towards the north. Foch considered the time had arrived for the Allies to return to the offensive. The Americans were now present in France in large numbers, and their presence invigorated the French armies. Their commander, General John Pershing was keen to use his army in an independent role. The British Army had also been reinforced by large numbers of troops that had returned from campaigns in Palestine and Italy, and large numbers of replacements previously held back in Britain by Prime Minister David Lloyd George.
Foch agreed on a proposal by Field Marshal Douglas Haig, the commander of the British Expeditionary Force, to launch an assault on the Somme, east of Amiens and southwest of the 1916 battlefield of the Battle of the Somme. The Somme was chosen as a suitable site for the offensive for several reasons. As in 1916, it marked the boundary between the British Expeditionary Force and the French armies, in this case defined by the Amiens-Roye road, allowing the two armies to cooperate. Also the Picardy countryside provided a good surface for tanks, which was not the case in Flanders. Finally, the German defences, manned by the German 2nd Army of General Georg von der Marwitz, were relatively weak, having been subjected to continual raiding by the Australians in a process termed Peaceful Penetration.
The Hundred Days Offensive opened with an attack by more than 10 Allied divisions, Australian, Canadian, British and French forces, and more than 500 tanks, on August 8, 1918. Through careful preparations, the Allies achieved complete surprise. This assault, spearheaded by the Australian Corps and Canadian Corps of the British 4th Army, that broke through the German lines, with tanks attacking German rear positions, is called the Battle of Amiens, which sowed panic and confusion. By the end of the day, a 15-mile-long gap had been created in the German line south of the Somme. The Allies had taken 17,000 prisoners and captured 330 guns. The total German losses were estimated to be 30,000, while the Allies had suffered about 6,500 killed, wounded and missing. The collapse in German morale led Erich Ludendorff to dub it “the Black Day of the German Army”.
During the first three days, the Allies had managed to gain 12 miles, but most of that had occurred on the first day. On August 10, the Germans began to pull out of the salient that they had managed to occupy during Operation Michael in March, back towards the Hindenburg Line. On August 15, 1918, Foch demanded that Haig continue the Amiens offensive, even though the attack was faltering, for the troops outran their supplies and artillery, as German reserves were being shifted to the sector. Haig refused, and instead he prepared to launch a fresh offensive by the British 3rd Army at Albert, which opened on August 21.
The offensive was a success. The German 2nd Army had been pushed back over a 34-mile front. Albert was captured in August 22 as the British 1rst Army widened the attack by another 7 miles on August 22. Bapaume fell on August 29. As artillery and ammunition were brought forward, the British 4th Army resumed its offensive at Amiens, as the Australian Corps crossed the Somme River on the night of August 31, breaking the German lines at Mont St Quentin and Peronne. The British 4th Army’s commander, General Henry Rawlinson, described the Australian advances of August 31–September 4 as the greatest military achievement of the war.
By September 2, the Germans had been forced back close to the Hindenburg Line, from which they had launched their Spring Offensive. Ferdinand Foch now planned a massive, concentric attack on the German lines in France with the various axes of advance converging on Liege in Belgium. This massive assault would later be called the Grand Offensive.
Foch’s Grand Offensive first attack began on September 26 by the American Expeditionary Force in the Meuse-Argonne area. Two days later, the Army Group under Albert I of Belgium launched an assault near Ypres in Flanders, called the Fourth Battle of Ypres. Both attacks made good progress initially but were then slowed by logistic problems, particularly in the American sector. But on September 29, General Douglas Haig launched the main attack on the Hindenburg Line with the British 4th Army. By October 5, the British 4th Army had broken through the entire depth of the Hindenburg defences. Meanwhile, on October 8, led by the Canadian Corps, the 1st and 3rd British armies broke through the Hindenburg Line at the Second Battle of Cambrai.
In October the German armies were forced back through the territory they had gained in 1914, but their retreat never turned into a rout. However, the Allies were pressing the Germans back towards the lateral railway line from Metz to Bruges, which had supplied their entire front in Northern France and Belgium for much of the war. As the Allied armies reached this line, the Germans were forced to abandon increasingly large amounts of heavy equipment and supplies, further reducing their morale and capacity to resist.
This collapse forced the German High Command to accept that the war had to be ended. The evidence of failing German morale also convinced many Allied commanders and political leaders that the war could be ended in 1918. Casualties remained heavy in all of the Allied fighting forces, as well as in the retreating German Army. Rearguard actions were fought at Ypres, Kortrijk, Selle, Valenciennes, the Sambre and Mons, with fighting continuing until the last minutes before the Armistice took effect at 11:00 on November 11, 1918. The last soldier to die was Private George Lawrence Price, a Canadian, two minutes before the armistice took effect.