What was the Hundred Days Offensive?
The Hundred Days Offensive was the run of Allied attacks on the Western Front from the Battle of Amiens on 8 August 1918 to the armistice of 11 November. British Empire, French, American and Belgian armies, coordinated by Ferdinand Foch, drove the German army back until Germany asked for an armistice.2
In the summer of 1918 the war on the Western Front turned. Between 8 August and 11 November the Allied armies attacked again and again, broke the Hindenburg Line and pushed the German army back towards the battlefields of 1914. It ranks among the greatest battles of the First World War.3
Background: Germany's last gamble
On 21 March 1918, Britannica records, Ludendorff opened a great offensive in the west, hoping to win before the Americans arrived in strength. The spring attacks pushed the Allies back, by Veterans Affairs Canada's account to within 70 kilometers of Paris, but overstretched and exhausted the German army. The Allies held, and Ferdinand Foch was given overall direction of their armies. By late August, the Imperial War Museums (IWM) record, more than 1.4 million American soldiers were in France.4
The last German offensive came in July on the Marne, the river where the German advance had been stopped in 1914 at the First Battle of the Marne. It failed, and on 18 July, IWM notes, a French-led counterattack drove the Germans back.5
Amiens, 8 August: the black day
According to Britannica, Foch planned the attack east of Amiens to protect the Paris to Amiens railway. General Sir Henry Rawlinson's British Fourth Army would attack, with the French First Army on its right. Its spearhead was the Australian Corps and the Canadian Corps, the latter under Lieutenant-General Sir Arthur Currie. Veterans Affairs Canada describes how Canadian units were first sent north towards Belgium as a decoy, and there was no long preliminary bombardment to warn the defenders.6
At 4:20 a.m. on 8 August, in thick mist, the guns opened and infantry and tanks went forward together. IWM counts 534 tanks, Britannica more than 600, with about 1,900 to 2,000 aircraft overhead. By evening, IWM writes, the Fourth Army had advanced about 13 kilometers on its main front and the French about 8; the Australian War Memorial gives about 11 kilometers for the Australians and nearly 13 for the Canadians.7
Ludendorff later called 8 August "the black day of the German Army". IWM counts around 30,000 German soldiers who surrendered during the battle, while Britannica gives German losses of more than 26,000, including some 12,000 prisoners, against more than 19,000 Allied killed and wounded. From then on, IWM writes, the German leadership, Kaiser Wilhelm II included, knew the war was lost.8
A new way of attacking
When the advance slowed on 11 August, the Allies struck elsewhere instead of battering on at the same spot, a pattern repeated all autumn that stretched German reserves. Infantry, artillery, tanks and aircraft now worked together, and the fighting moved out of the trenches into the open. In what IWM calls the Second Battle of the Somme, the Allies retook Albert and Bapaume by the end of August, on the river of the 1916 Somme offensive.9
The Australians: Mont St Quentin and Péronne
The Australian War Memorial tells how Lieutenant-General Sir John Monash kept his Australian Corps moving east along the Somme. Mont St Quentin, a hill overlooking the river and the town of Péronne, was the key to the German line there. On 31 August the 2nd Australian Division attacked it at 5 am from the north-west, an unexpected direction. The attackers reached the summit, but German counterattacks drove them off that evening; reinforcements retook it on 1 September, and by the night of 3 September they held Péronne, at a cost of about 3,000 casualties.10
Canada's Hundred Days
The Canadian Corps had made its name at Vimy Ridge in 1917, and in 1918 it served as a spearhead. By Veterans Affairs Canada's account, after Amiens it moved north to Arras, attacked on 26 August and on 2 September broke the Drocourt-Quéant Line in front of the main Hindenburg position. On 27 September Currie sent his divisions across a dry section of the unfinished Canal du Nord, some 2,500 meters of its length by the department's measure, behind what it calls the heaviest single-day bombardment of the war, and on to Bourlon Wood. Cambrai followed in October.11
The campaign ended where the British war had begun: Canadian troops entered Mons, where British soldiers had fought in August 1914, in the early hours of 11 November. Veterans Affairs Canada counts an advance of 130 kilometers and about 32,000 prisoners, at a cost of more than 6,800 Canadians and Newfoundlanders killed and about 39,000 wounded.12
The Americans at St Mihiel and in the Meuse-Argonne
Under General John J. Pershing the Americans attacked the St Mihiel salient from 12 to 15 September, which IWM calls the only American-led attack of the war. They were then shifted to the Meuse-Argonne Offensive, which the National WWI Museum dates from 26 September. It lasted until the armistice and, the museum notes, remains the bloodiest battle in American military history, with over 26,000 killed and 95,000 wounded.13
Breaking the Hindenburg Line
The decisive blow fell on 29 September at the St Quentin Canal, which the Germans had built into the Hindenburg Line. Rawlinson's Fourth Army attacked with British, Australian and American troops, with the French First Army to the south. At Riqueval the 137th Brigade of the 46th (North Midland) Division crossed the canal, and IWM records that the division alone took more than 4,000 prisoners. The Western Front Association gives about 8,000 British, 13,000 American and 2,500 Australian casualties, against 36,000 German, most of them prisoners.14
Flanders and the Belgian army
In the north the Belgian army, which had held a strip of Flanders behind the Yser since 1914 while almost all of Belgium was occupied, joined the general offensive. The Belgian public broadcaster VRT recalls that King Albert I had long refused to commit his troops to a great offensive. On 28 September 1918 the Flanders Army Group attacked under his command: the Belgian army, the British Second Army and French troops. Within a week, according to Canada's Department of National Defence, the army group took about 10,000 prisoners and over 300 guns. It went on to Ostend, and Britannica adds Bruges and a forced crossing of the Lys.15
Why did the Hundred Days Offensive succeed?
It succeeded because the Allies combined infantry, artillery, tanks and aircraft, struck one sector after another so the Germans could never rest or shift their reserves, and drew on growing numbers of fresh American troops. The German army, exhausted and short of men after its spring offensives, lost heart, and its soldiers surrendered in large numbers.
The German side
For German soldiers the autumn of 1918 was a long fighting retreat, and IWM stresses how much poor morale contributed to Allied victories. Soon after the Hindenburg Line broke, Ludendorff demanded an immediate armistice. When he saw how severe the terms would be he wanted to fight on; the politicians refused, and Wilhelm II accepted his resignation on 26 October. Ludendorff later blamed defeat on a stab in the back by the home front, a legend that, Britannica writes, poisoned public life in the Weimar Republic.16
How many died in the Hundred Days?
There is no agreed total. IWM gives around 700,000 Allied and around 760,000 German casualties between August and November 1918. The National WWI Museum and Memorial gives close to 1,070,000 Allied and 1,172,075 German, many of the Germans taken prisoner. These totals include killed, wounded, missing and captured, and armies counted them differently.17
How each nation remembers it
Canadians remember "Canada's Hundred Days" as the high point of their corps' war. The Australian War Memorial notes that Mont St Quentin is sometimes regarded as the finest achievement of the Australian Imperial Force. Americans remember the Meuse-Argonne as their army's main contribution and costliest battle. IWM observes that accounts of Amiens usually focus on the Australians and Canadians, almost ignore the French and often marginalize the British.18
The end, and the battlefield today
The Allies had expected to need a final offensive in the spring of 1919, IWM notes, but the German army broke sooner. Fighting went on until the armistice took effect at 11 am on 11 November 1918. At Riqueval Bridge a Western Front Association plaque recalls the 46th Division, and memorials at nearby Bellenglise and Bellicourt honor the Australian and American soldiers who fought there.19
