What defined warfare in the First World War?

This guide describes how the First World War buried the war of movement in mud and wire. Fought from the Marne to the Somme, its battles defined a generation and an age of industrial slaughter.

How did the trench warfare of the First World War take shape?

The guide points to First Ypres in 1914, when the trenches reached the sea. It marked the moment the First World War settled into a static front of mud and wire.

Which First World War battles does the guide treat as the most defining?

The guide highlights the Marne in 1914, the miracle that saved Paris, Verdun in 1916, remembered by the words they shall not pass, and the Somme in 1916, a million casualties and the symbol of the war. Together they define the industrial slaughter of the First World War.

Which battles does the First World War guide cover?

This guide to the greatest battles of the First World War covers the Marne, First Ypres, Gallipoli, Verdun, the Somme and Passchendaele, six battles fought between 1914 and 1917.

When was the First World War?

From 1914 to 1918. The battles here run from the opening clashes of 1914 to the final offensives of 1918.

Why was the First World War so deadly?

Industrial firepower had outrun tactics. Machine guns, massed artillery and barbed wire made attacking across open ground catastrophic, while generals kept ordering frontal assaults.

Who won the Battle of Tannenberg?

Germany. Between 26 and 30 August 1914 the German Eighth Army, led by Paul von Hindenburg and Erich Ludendorff, encircled and almost destroyed the Russian Second Army in East Prussia. Its commander, General Alexander Samsonov, took his own life.

What was the Miracle of the Marne?

The French name for the First Battle of the Marne, 5 to 12 September 1914. With German armies about 40 kilometres from Paris, French and British forces counterattacked and drove them back to the river Aisne, ending Germany's hope of defeating France quickly.

Who won the First Battle of Ypres?

Neither side won outright. From 19 October to 22 November 1914 French, British and Belgian troops held Ypres against repeated German attacks, so the Allies kept the town, but no one broke through. Both armies were exhausted and the front settled into trenches.

The Greatest Battles of the First World War: a guide

At a glance
	Battle	Date	Forces	Casualties
1	The Marne	1914	~2,000,000	~513,000
2	First Ypres	1914	~1,020,000	~295,000
3	Gallipoli	1915	~804,000	~507,000
4	Verdun	1916	~1,000,000	~714,000
5	The Somme	1916	~1,250,000	~1,085,000
6	Passchendaele	1917	-	-

Quick answer

What were the biggest battles of World War I?

The greatest battles of the First World War were the Marne and First Ypres in 1914, Gallipoli in 1915, Verdun and the Somme in 1916, and Passchendaele in 1917. Verdun and the Somme became months-long grinding machines, and the Somme, with a million casualties, became the symbol of the war.

The First World War buried the war of movement in mud and wire. From the Marne to the Somme, these battles defined a generation and an age of industrial slaughter.

The Marne, 1914. The miracle that saved Paris.

First Ypres, 1914. The trenches reach the sea.

Gallipoli, 1915. The Dardanelles gamble and the ANZAC legend.

Painting of Australian soldiers climbing a steep, scrubby ridge above Anzac Cove under fire, with a yellow rock pinnacle rising behind them — Australian soldiers of the covering force climbing the slopes above Anzac Cove on 25 April 1915, with the rock pinnacle known as the Sphinx behind them. Anzac, the landing 1915, painted by George Lambert in 1920 to 1922. Public domain

Verdun, 1916. They shall not pass.

The Somme, 1916. A million casualties, the symbol of the war¹.

Passchendaele, 1917. The Third Battle of Ypres, a byword for the mud.

A lone soldier on a muddy track lined with shattered tree trunks — A soldier runs along a track through the shattered trees of Chateau Wood during the Third Battle of Ypres in 1917. Photograph by Frank Hurley, probably posed. Public domain

See these battles set beside every other era in Battles That Changed the World.

Why the First World War changed war forever

The First World War was where industry overwhelmed tactics. Machine guns, quick-firing artillery and barbed wire made the old attacks suicidal, and the fighting froze into a line of trenches from the Channel to Switzerland. Battles like the Somme and Verdun became months-long grinding machines that killed hundreds of thousands for a few miles of mud².

British soldiers resting in a trench while one keeps watch over the parapet — Men of the 11th Battalion, Cheshire Regiment, in a captured German trench at Ovillers-la-Boisselle during the Battle of the Somme, July 1916. Photograph by John Warwick Brooke. Public domain

What was the deadliest battle of World War I?

There is no single agreed answer, but the Somme is the battle most often named. Between 1 July and 18 November 1916 more than one million men were killed, wounded or captured there. Verdun, the longest battle of the war, cost around 714,000 casualties, and in the East Russia's Brusilov offensive took a toll on the same scale.

The Somme's first day, 1 July 1916, is still the bloodiest in British military history: 19,240 British soldiers were killed and more than 57,000 became casualties. Over the next four and a half months the British advanced at most seven miles¹. German losses are disputed. German figures run from about 237,000 to 429,000, while British estimates run from about 440,000 to 600,000³.

Verdun lasted 302 days, from 21 February to 18 December 1916. Hannes Heer and Klaus Naumann put French casualties at 377,231 and German at 337,000, about 714,000 in all². Our full account of the Battle of Verdun follows the fight for the forts.

The Eastern Front had its own slaughter. It opened with a German triumph at Tannenberg, 26 to 30 August 1914, where the Russian Second Army was encircled and almost destroyed⁴. Two years later Russia struck back. The Brusilov offensive, 4 June to 20 September 1916, was Russia's greatest feat of arms in the war and a crisis for Austria-Hungary. Russian casualties are put at between 500,000 and 1,000,000, Austro-Hungarian losses at around 616,000 and German losses at between 148,000 and 350,000⁵.

How did the First World War end on the battlefield?

The war was decided on the Western Front in 1918. Germany's spring offensive, launched on 21 March, won ground but not the war. From 8 August, beginning at Amiens, the Allies' Hundred Days Offensive drove the German army back through the Hindenburg Line and led directly to the armistice of 11 November 1918.

Russia's exit from the war after the Treaty of Brest-Litovsk freed nearly 50 German divisions for the West. The German high command saw one last chance: beat the Allies before the United States could bring its full strength across the Atlantic⁶. The attacks drove the Allies back as far as the river Marne, where Germany's advance had been stopped in 1914, but they petered out by July. Ferdinand Foch then counterattacked in the Second Battle of the Marne⁷. Read how the first stand saved Paris in the Battle of the Marne.

At Amiens on 8 August, more than ten Australian, Canadian, British and French divisions attacked with more than 500 tanks, on a plan shaped by the Australian general John Monash. From then on the Allies won battle after battle. On 29 September they broke the Hindenburg Line at the St Quentin Canal. The "Hundred Days" actually lasted 95, and they ended with the armistice⁷.

Each battle has its full account below. See how this industrial slaughter fits the wider story in the greatest battles of all time.

Sources and notes

Numbered notes in the text point to the works below.

Imperial War Museums, “Battle of the Somme” ↩ a b
Wikipedia, “Battle of Verdun” (casualty totals from Heer and Naumann and from Philpott, cited there) ↩ a b
Wikipedia, “Battle of the Somme” (British and German casualty estimates cited there) ↩
Wikipedia, “Battle of Tannenberg” ↩
Wikipedia, “Brusilov offensive” ↩
Wikipedia, “German spring offensive” ↩
Wikipedia, “Hundred Days Offensive” ↩ a b

The Greatest Battles of the First World War