1918: The Real German Spring Offensive & the Allied Hundred Days

Military History: World War I

Chapter 9 · 1918: The Real German Spring Offensive & the Allied Hundred Days

For three years the Western Front barely moved. In 1918 it moved dramatically — twice. In the spring, German armies broke through further than anyone had since 1914. By the summer, the Allies had learned to do the same thing better, and in about a hundred days they pushed the German army into defeat. This chapter shows how both sides finally solved the problem set out in Chapter 4.

Germany's Last Chance

A Window of Time

The United States had joined the war (Chapter 7), but its army would take months to arrive in large numbers. Germany had perhaps half a year of numerical advantage.

Troops From the East

Russia's collapse (Chapter 8) let Germany move around 50 divisions to the Western Front, though many troops stayed in the east.

A Weakening Home Front

The blockade (Chapter 7) had left Germany short of food and materials. Ludendorff knew the army couldn't fight a long war of attrition much longer.

New Tactics: How Germany Broke In

Method	What it did differently
Short, intense bombardment	Instead of days of shelling (Chapter 6), the artillery expert Georg Bruchmüller planned a few hours of accurately targeted fire, mixing gas and high explosive, aimed at artillery, headquarters, and communications. The enemy got little warning.
Storm troops	Specially trained assault units moved forward in small groups, bypassing strongpoints rather than attacking them, and pushed deep into the enemy's rear. Follow-up troops dealt with the bypassed positions.
Defence in depth	Rather than trying to hold the front line at all costs, attackers aimed to disrupt the whole defensive zone so reserves couldn't react in time.

Tested in the East These ideas had been tried at Riga in September 1917 (Chapter 8) and at Caporetto in Italy in October 1917, where Austro-German forces broke the Italian army. They were close cousins of Brusilov's methods from 1916.

The Spring Offensive: 21 March – 18 July 1918

21 March Operation Michael strikes the British Fifth and Third Armies near St Quentin, in thick fog. The British front is overrun and the Germans advance further in a few days than in the previous three years.
26 March With the Allies in real danger of being split apart, the French general Ferdinand Foch is given the job of coordinating the Allied armies — soon becoming supreme commander on the Western Front.
April Operation Georgette attacks in Flanders. Haig issues his "backs to the wall" order on 11 April, telling his troops there must be no retreat.
May–June The Blücher-Yorck offensive against the French on the Aisne reaches the River Marne again, about 90 km from Paris. Newly arrived American troops fight at Château-Thierry and Belleau Wood.
15–18 July A final German attack near Reims fails; on 18 July French and American forces counter-attack at the Second Battle of the Marne. The initiative passes to the Allies for good.

Why a Tactical Success Became a Strategic Failure Ludendorff reportedly summed up his approach as: "We chop a hole. The rest follows." The offensives had no clear strategic goal and kept switching direction. Storm troops carried supplies for only a few days, and German soldiers advancing across the old Somme battlefields often stopped to loot Allied food stores. The Germans gained large areas of ground — but it was mostly worthless, and they now held a longer line with fewer men. Around 688,000 German soldiers became casualties, including many of the irreplaceable elite storm troops, against about 863,000 Allied casualties.

The Paris Gun

From March to August, a German super-long-range gun shelled Paris from more than 100 km away, killing around 250 people. It was a remarkable piece of engineering with almost no military value — a weapon meant to frighten.

The Allies' Answer: Combined Arms

By mid-1918 the British, French, and American armies had learned to combine every tool developed since 1915 into a single, coordinated system — far more effectively than any one weapon on its own.

Artillery That Hit What It Aimed At

New methods let gunners fire accurately without warning "registration" shots, and locate enemy guns by sound and flash. Surprise returned.

Tanks and Aircraft

Hundreds of improved tanks crushed wire and machine-gun posts, while aircraft spotted for artillery, attacked ground targets, and fought for control of the air.

Better Infantry Tactics

Allied infantry now attacked in small groups built around light machine guns, rifle grenades, and Lewis guns — the same basic idea as the German storm troops.

The "Learning Curve" Pays Off Chapter 6 introduced the debate over whether the British Army learned from the Somme. 1918 is the strongest evidence that it did: the same army that lost 19,240 men killed on one day in 1916 was, two years later, winning a long series of battles with far lower losses per mile gained.

The Hundred Days: 8 August – 11 November 1918

Amiens, 8 August 1918

A surprise attack led by the Australian and Canadian Corps, planned in large part by the Australian commander John Monash, used over 500 tanks, careful artillery, and aircraft. The Allies advanced about 11 km on the first day, and thousands of German soldiers surrendered. Ludendorff called it "the black day of the German Army" — not because of the ground lost, but because German troops were surrendering in large numbers.

August–September The Allies attack in a series of short, hard blows at different points along the front, stopping each attack before it outran its artillery, then striking somewhere else.
12 September The American First Army, under General John Pershing, takes the Saint-Mihiel salient in its first big independent operation.
26 September The Meuse-Argonne Offensive begins — the largest and deadliest battle in American military history, with around 26,000 Americans killed by November.
29 September British and Australian forces break the Hindenburg Line at the St Quentin Canal; British troops cross the canal using lifebelts and rafts. The same day, Ludendorff tells the German leadership it must seek an armistice.
October–November The German army retreats across Belgium and northern France, fighting as it goes. Its allies collapse: Bulgaria, the Ottoman Empire, and Austria-Hungary all sign armistices.

Who Won the War on the Western Front? British memory tends to focus on the British Army, American memory on the US arrival, and French memory on France's long endurance. In reality, all three mattered: the French army held the longest share of the line throughout; the British Empire's forces, including Australians and Canadians, did much of the attacking in the Hundred Days; and American manpower, even more than American fighting, convinced German leaders they couldn't win.

Questions to Sit With

Germany's spring offensive won more ground than any attack since 1914, yet it lost the war. Why can capturing ground be a mistake?

Why did combining many weapons work in 1918, when no single new weapon had worked before?

Why does each Allied country tend to remember itself as the one that won the war? Is any of them right?

Quick Reference — Chapter 9

Germany attacked in 1918 before American troops arrived in force, using about 50 divisions freed by Russia's collapse
New methods: Bruchmüller's short, accurate bombardments and storm troops infiltrating past strongpoints — tested at Riga and Caporetto
Spring Offensive, 21 March – 18 July 1918: Michael, Georgette, Blücher-Yorck, and the final attack near Reims; Foch became Allied coordinator; Haig's "backs to the wall" order
The offensives gained ground but had no clear goal, outran supplies, and cost about 688,000 German casualties, including irreplaceable storm troops
The Allies used combined arms: accurate artillery, hundreds of tanks, aircraft, and small-group infantry tactics
Hundred Days, 8 August – 11 November: Amiens ("the black day of the German Army"), Saint-Mihiel, the Meuse-Argonne, and the breaking of the Hindenburg Line on 29 September
Ludendorff demanded an armistice on 29 September; Germany's allies collapsed in October and November

What's Next

Chapter 10: Capstone: The Real Armistice (1918) & the Military Legacy of the First World War.