Officers of the 2nd Battalion, King's Own Yorkshire Light Infantry, 62nd Division, conferring with French and Italian officers in the Bois de Reims during the Battle of Tardenois, 24 July 1918. (1918) by Second Lieutenant Thomas Keith AitkenOriginal Source: https://www.iwm.org.uk/collections/item/object/205231562
The Hundred Days Offensive, also known as the Advance to Victory, was a series of Allied successes that pushed the German army back to the battlefields of 1914.
It came after the German Spring Offensive, which began in March 1918 and came close to breaking the Allied front line. But the allies had just managed to hold on.
In the Second Battle of the Marne (15 July-6 August 1918), the Germans once again failed to deliver a decisive blow and on 18 July the Allied counter-attack, led by the French, pushed them back again.
The Marne was to be the last German offensive. The Allies now seized the initiative.
General Ferdinand Foch, the Commander-in-Chief of the Allied Armies, at Sarcus, 17 May 1918. (1918) by French Official PhotographerOriginal Source: https://www.iwm.org.uk/collections/item/object/205084494
Cooperation was a significant factor in the success of the offensive. General Ferdinand Foch was appointed Commander-in-Chief of the Allied Forces on the Western Front in March 1918. He directed overall strategy which ensured a coordinated approach by the French, British and American armies.
Receiving photographic plates from the observer Lieutenant J. H. Snyder, after a reconnaissance flight, and rushing them to the field studio by a motorcycle. Pilot: Major J. N. Reynolds. Aircraft: Salmson 2 A2 biplane. Unit: 91st Aero Squadron. Gondreville-sur-Moselle aerodrome, 6 August 1918. (1918)Original Source: https://www.iwm.org.uk/collections/item/object/205315062
The Hundred Days Offensive actually spanned 95 days: beginning with the Battle of Amiens on 8 August 1918 and ending with the Armistice on 11 November 1918.
By the summer of 1918 the Allies had control of the skies. British, French and American aircraft at times outnumbered their German counterparts five to one.
Their dominance in the air enabled the Allies to photograph German positions and direct their artillery fire from aircraft as well as prevent the Germans from doing the same.
This allowed the Allies to conceal their preparations and keep the German Army guessing about where the next attack would come from.
60 pounder guns in action during the Battle of Amiens in August 1918. (1918) by Canadian Official Photographer, Lt W Rider-RiderOriginal Source: https://www.iwm.org.uk/collections/item/object/205195645
At 4:20 a.m. on 8 August 1918 the Battle of Amiens began. It was a morning of heavy fog and the Germans were taken completely by surprise.
Some German officers were reportedly captured while still eating their breakfast. The Australian Corps and Canadian Corps spearheaded the attack and advanced quickly behind the 534 tanks, reaching their objectives within hours.
When the advance was halted on 11 August, the Allies shifted their attack to a different part of the line.
This new strategy contributed to the success of the offensive by continually stretching the German army’s resources and manpower.
The Allies continued to attack in this way throughout the summer and autumn of 1918, giving the increasingly exhausted and depleted German army little respite.
By the end of August the Allies had captured Albert, Bapaume, Noyon and Peronne during the Second Battle of the Somme.
American gunners of the "A" Battery, 108th Field Artillery Regiment (formerly 2nd Regiment, Field Artillery and detachment of the 1st Cavalry, Pennsylvania National Guard) firing 75 mm guns near Varennes-en-Argonne, 3 October 1918. (1918) by US Official PhotographerOriginal Source: https://www.iwm.org.uk/collections/item/object/205086265
By the end of August there were over 1.4 million American troops in France. It was the arrival of these fresh troops that enabled the Allies to continue fighting after their significant losses during the German Spring Offensive.
The attack on the St Mihiel salient (12-15 September) was the first and only American led attack during the First World War.
It was a relatively easy victory as it caught the German Army on the retreat but it established the American army as a formidable fighting force.
With the success at St Mihiel the Americans were moved to support the ambitious attack planned by Marshal Foch at the Battles of Meuse-Argonne.
This was the main contribution of the American army in the First World War and the losses were high amongst their inexperienced troops.
Troops of the 107th Infantry Regiment, American 27th Division following tanks near Beauquesnes, 13 September 1918. One platoon of infantry follows one tank. (1918) by US Official PhotographerOriginal Source: https://www.iwm.org.uk/collections/item/object/205218820
The Allied armies deployed new tactics to overcome the stalemate of trench warfare.
Artillery, tanks and air power were successfully utilised in a new coordinated all-arms approach. Allied success saw fighting move from the trenches out into the open.
Allied artillery dominated the battlefield, paving the way for a breakthrough.
However, German machine guns hindered their advances so that most attacks were made under cover of darkness.
Battle of St Quentin Canal (Saint-Quentin). Mark V Tanks going forward with the 'cribs' carried to enable them to cross the Hindenburg Line, Bellicourt, 29th September 1918. (1918) by Second Lieutenant David McLellanOriginal Source: https://www.iwm.org.uk/collections/item/object/205087470
Tanks were still relatively new weapons and were most useful for crushing barbed wire obstacles, destroying machine-gun posts and in village fighting.
They would be followed by small groups of infantry. The tanks carried cribs, frames made of wood and steel, which could be dropped to enable them to cross wide trenches.
The rapid movement caused difficulties in getting supplies to the front, and few of the soldiers who were in the field in 1918 had received training in open warfare.
Battle of St. Quentin Canal. Brigadier-General John Vaughan Campbell VC addressing men of the 137th Brigade (46th Division) on the Riqueval Bridge over the St. Quentin Canal (part of the German's Hindenburg Line) which they crossed on 29 September 1918. (1918) by Second Lieutenant David McLellanOriginal Source: https://www.iwm.org.uk/collections/item/object/205216479
By late September the Allied forces were facing the Hindenburg line, a series of heavily fortified positions that formed the main German defences.
The Battle of St Quentin Canal (29 September 1918) was a crucial victory that broke through one of the strongest sections of the Hindenburg Line.
Following the complete breakthrough of the Line in early October, General Ludendorff is reported to have said that the “situation of the [German] Army demands an immediate armistice in order to save a catastrophe”.
Although it would still be several weeks before the Armistice, it was clear that Germany now could not win the war.
Battle of the St Quentin Canal (Saint-Quentin). Prisoners in a Clearing Depot, Abbeville, 2nd October 1918. (1918) by Second Lieutenant David McLellanOriginal Source: https://www.iwm.org.uk/collections/item/object/205194727
Throughout the Hundred Days Offensive, poor morale in the Germanarmy contributed significantly to the Allied victories.
The failure of the Spring Offensive and the surprise counter-attack at Amiens demoralised the German troops.
Around 30,000 German soldiers surrendered during the Battle of Amiens.
Ludendorff described the first day of this battle as the “black day of the German Army”.
Huge numbers of German prisoners were also taken at the Battle of St. Quentin Canal.
The 46th Division alone captured over 4,000 men. General Sir Henry Rawlinson remarked that the Hindenburg Line would have been impregnable if it had been defended by the German army of two years earlier.
Canadian troops marching through the streets of Mons on the morning of 11 November 1918. (1918) by Canadian Official Photographer, W Rider-RiderOriginal Source: https://www.iwm.org.uk/collections/item/object/205195646
The Canadian Corps reached Mons at 4:00 a.m. on 11 November 1918. They were surrounded by jubilant civilians as they marched through the streets.
Mons had been the location of the first battle fought by the British army in August 1914 and had been occupied by the Germans for the duration of the war.
Fighting on the Western Front continued right up to the last minute until finally, at 11:00 a.m. on 11 November 1918, the Armistice came into effect and hostilities ceased.
American wounded being treated by staff of the 110th Sanitary Train, 4th Ambulance Corps (US 1st Division) in an old, destroyed church at Neuville-sur-Ornain, 20 September 1918. (1918) by US Official PhotographerOriginal Source: https://www.iwm.org.uk/collections/item/object/205215793
The Hundred Days Offensive brought victory, but at a huge cost.
Allied casualties between August and November 1918 were around 700,000. German casualties were slightly higher at around 760,000.
Initially the Allies had not expected the offensive to end the war but were planning their final attack for the Spring of 1919.
However, their impressive feat of arms during the Hundred Days broke the spirit of the German army and inflicted losses from which they could not recover.
Visit iwm.org.uk to explore how the First World War changed our world.
Curated by Maria Anthony, Assistant Curator, First World War and Early 20th Century