World War One: The global conflict that defined a century

'A war to end all wars'

The First World War was the first truly global conflict – the battle raged not just in the trenches of the Western Front but in Africa, the Middle East and Asia.

Huge armies deployed new weapons to devastating effect. Over nine million soldiers and an unknown number of civilians lost their lives. Empires crumbled, revolution engulfed Russia, and America rose to become a dominant world power.

28 June 1914

Assassination of Franz Ferdinand

France and Russia formed an alliance in 1894. Britain reaches ‘understandings’ with both but it does not commit to fight in case of war.

Tensions rise across Europe. Franz Ferdinand, heir to the Austro-Hungarian throne, is shot dead in Sarajevo, capital of the Austrian province Bosnia. Franz Ferdinand’s killer, Gavrilo Princip, is backed by Serbian terrorist group ‘the Black Hand’. Austria-Hungary issues Serbia with an ultimatum, calling for Serbia to allow Austria-Hungary to be represented in proceedings against the guilty. Serbia agrees to most of the demands, but not this one.

Margaret MacMillan describes the events leading up to Franz Ferdinand's assassination. Clip from 1914: Day by Day, 28 June (Radio 4).

28 July 1914

Europe descends into war

As Europe stands on the brink of war, British proposals for a meeting of the great powers are ignored.

Backed up by Germany, Austria-Hungary declares war on Serbia on 28 July. Russia quickly steps in to protect the small nation and mobilises its army. Germany responds by declaring war on Russia. France is Russia's ally and begins mobilising its forces. As the armies mobilise war becomes almost inevitable. Many believe the war will be a short manageable conflict, but the crisis unfolds so quickly that no statesman is able to regain control of it.

Margaret MacMillan describes Austria’s ultimatum to Serbia. Clip from 1914: Day by Day, 23 July (Radio 4).

4 August 1914

Britain declares war on Germany

Germany attacks France first through neutral Belgium to eliminate any threat from the west before facing Russia in the east.

Britain and the other great powers of Europe guarantee to protect Belgium’s borders. Belgium appeals to Britain and Britain declares war. After Britain’s entry to the war, the German army lays waste to the country. The British Empire is also dragged into the conflict and the war in Europe starts to expand across the globe.

Jeremy Paxman describes the last hours before war was declared. Clip from Britain's Great War (BBC One).

7 August 1914

The war in Africa

The first shots of World War One are fired in Africa.

By 1914 the German Empire has four colonies in East, West and South Africa. British and French forces invade Togoland the site of a key German wireless station, Kamina. It provides communications for German ships in the Atlantic. The Germans destroy it to stop it falling into the Allies’ hands and soon after surrender Togoland.

Akwasi Sarpong of BBC World Service on the importance of Kamina.

23 August 1914

The Battle of Mons

The Battle of Mons in Belgium is the British Army's first engagement in France.

The German Kaiser orders the destruction of Britain's ‘contemptible little army’ and 70,000 British soldiers are attacked by 160,000 German troops. Both sides use quick-firing artillery and machine guns to devastating effect. Outgunned and outnumbered Britain's tiny Expeditionary Force suffers heavy casualties and is forced to retreat. On the back of this humiliation Britain starts recruiting a large army for the first time.

The Battle of Mons. Clip from Our World War (BBC Three).

5 September 1914

The Battle of the Marne

As the German Army advances towards Paris, French and British soldiers counterattack along the line of the River Marne.

After bloody battles, with over 250,000 casualties on both sides since the war began, the German army and the Allies try to outflank each other to the north until they reach the Belgian coast. The two armies dig in. Defensive lines are drawn right across north-east France. This marks the end of mobile battles and the beginning of four years of trench warfare on the Western Front.

French soldiers at the Battle of the Marne.

10 October 1914

The Indian Army joins the war

At the Battle of La Bassee in northern France Indian soldiers join the Allies for the first time.

Britain calls on its Empire and 1.5 million Indian soldiers and 1.3 million Canadians, Australians, New Zealanders and South Africans fight on the allied side. France also draws on its colonies in Africa, including the famous Zouaves – with their bright red and blue uniforms – and the Spahis, both from North Africa. The war is now truly global.

Watch 30,000 Indian troops arrive in Marseille in 1914. Clip from The World's War (BBC Two).

31 October 1914

Siege of Tsingtao

In the Far East, Britain has an ally – Japan. Fresh from victory in the Russo-Japanese war, the Japanese flex their military muscles.

In the autumn of 1914 British and Japanese forces attack the port of Tsingtao (Qingdao) – a German colony - in China. Although the Germans put up a firm resistance a force of 23,000 Japanese soldiers seizes control. Japan also takes over Germany’s colonies in the Caroline, Mariana and Marshall Islands. Later in the war, Japan sends warships to help protect Allied shipping in the Mediterranean.

3 January 1915

First use of poison gas

Both sides experiment with tear gas in the first winter of the war.

But in January 1915 the Germans use a more deadly chemical – xylyl bromide – killing around 1,000 Russian troops at Bolimov, on the Eastern Front. At Ypres in Belgium gas is used for the first time on a large scale. Germany unleashes thousands of canisters of chlorine gas, causing over 7,000 casualties among the British, Canadian and French. Its effect is devastating, terrifying soldiers and causing uproar at home.

German soldiers stand downwind as they release poisonous gas.

25 April 1915

The Gallipoli campaign

Bogged down in a stalemate on the Western Front, the Allies attack Germany's allies in the Middle East, the Ottoman Turks.

Australian, New Zealand, British, French and Indian troops mount an amphibious landing to take the peninsula of Gallipoli, 100 miles south of the Ottoman capital Constantinople. But the Allies are unable to break out of their beachheads and suffer a crushing defeat by the end of the year. Almost a third of the New Zealand troops are killed and there are 28,000 Australian casualties. The Turks suffer 200,000 casualties.

Australia, New Zealand and the birth of the Anzac spirit.

7 May 1915

The sinking of the Lusitania

One of the most terrifying new weapons of World War One is the U-Boat. These German submarines patrol Atlantic and Mediterranean trade routes.

A civilian passenger liner, the Lusitania, is sunk off the coast of Ireland by a torpedo fired by a U-Boat. More than 1,200 people die – including 128 Americans. Although Germany had issued warnings, the world is shocked by this unprecedented attack on civilians. This devastating event pushes America closer to joining the war.

Survivor Parry Jones speaking in 1962 about why passengers did not heed German warnings. Clip from Fifty Fathoms Deep (BBC One 1962).

27 January 1916

Conscription introduced in Britain

By 1916 heavy losses on the Western Front mean Britain’s volunteer army needs reinforcements. On 27 January the government introduces conscription.

All single men aged 18 to 41 can now be sent to war, although thousands are exempted because they have vital jobs in industry which are important to the war effort. In 1917 the US, along with Canada and New Zealand, is forced to bring in conscription after only 73,000 people volunteer for the Western Front.

250,000 under-age soldiers joined up, but why were they so keen?

21 February 1916

Battle of Verdun

At the start of 1916 the opposing forces are fighting a frustrating war of attrition on the Western Front.

The Germans plan an offensive on a series of forts around the town of Verdun, believing the French will throw huge resources into defending it only to be annihilated. This is the longest single battle of World War One and lasts nine months. The Germans fail to break through or exhaust the French army and when the battle is over both sides have lost around 300,000 soldiers. For the French, Verdun becomes a symbol of the sacrifice of their country’s youth during the war.

French soldiers at the Battle of Verdun.

31 May 1916

Battle of Jutland

The German fleet leaves the safety of its ports in a bid to shell the English coast and attack an element of the British fleet.

It meets the full force of the British Navy off the coast of Denmark, at Jutland. In the biggest naval battle of the war the British lose more ships than the Germans and fail to destroy the German High Seas Fleet. But the German Navy retreats and remains bottled up in its North Sea and Baltic ports. It does not want to risk losing more ships in a full-scale battle. For the rest of the war Germany relies on U-boats to attack British supply lines.

Dr Sam Willis explains why the Royal Navy moved to Scapa Flow.

1 July 1916

The Battle of the Somme

The Battle of the Somme is one of the largest and bloodiest conflicts of World War One. Nearly 20,000 British soldiers die on the first day.

It is part of a massive joint offensive by the Allies on their fronts in France, Italy and Russia. British Commander-in-Chief General Haig hopes to end the deadlock on the Western Front at the Somme. He thinks an artillery bombardment will silence the German guns and allow his infantry to break through. But the Germans dig in and fire on the charging Allied soldiers with machine guns. By November the Allies have advanced five miles. There are over half a million casualties on each side.

Francine Stock looks back at the box office hit of 1916.

6 April 1917

America enters the war

In January 1917 Germany sends a message to Mexico, the infamous 'Zimmerman' telegram, inciting it to attack the US.

In February the Germans restart their U-boat campaign against commercial ships headed from America to Britain and many American civilians lose their lives. In April, President Woodrow Wilson persuades Congress that America should declare war on Germany. The following year, the arrival of American troops is a great blow to German morale and a decisive turning point in the war. The German army now faces the economic and military might of the world’s rising power.

Luis Fajardo explains how the US came to enter the war.

8 November 1917

Revolution in Russia

In March 1917 there is a popular uprising in Russia and Tsar Nicholas II abdicates.

The provisional government continues with the highly unpopular and unsuccessful war. In November the Bolsheviks, led by Lenin, seize power under the slogan of “Peace, bread, land”. Russia leaves the war, signing an armistice in December. In the peace treaty Germany gains large swathes of Eastern Europe.

Russian soldiers join protests during the October revolution.

21 March 1918

Germany launches the Spring Offensive

With its armies now free from the threat of Russia in the east, Germany mounts a series of major offensives in France in the spring.

The Germans make a huge breakthrough on a 50-mile front south of Arras, pushing the Allies back 40 miles. The overstretched German Army is unable to sustain its attack. Time is running out as American troops begin to arrive in great numbers.

July 1918

Hundred Days Offensive

Bolstered by American troops, the Allies carry out a series of sustained attacks, known as the Hundred Days Offensive.

On 18 July the French, supported by 85,000 fresh US troops, counter-attack the German forces on the Marne and force them to retreat. In August, with more than 10 divisions of soldiers and 50 tanks, backed up by the Royal Air Force, the Allies launch a surprise attack at Amiens. In a series of battles the German Army is pushed further east and the German commanders privately concede the war is lost.

The Battle of Amiens begins. Clip from Our World War (BBC Three).

11 November 1918


Before the Allied armies can invade Germany, an armistice is signed, bringing the war on the Western Front to an end.

In a train carriage at Compiègne in northern France, the Germans surrender and agree to withdraw their forces from France and Belgium. Many German soldiers feel betrayed. The fighting ceases at 11am on 11 November 1918, which for Britain, France and America becomes the time when the war dead are honoured. In 1919 The Treaty of Versailles imposes harsh terms on Germany forcing them to accept the blame for the war and pay huge reparations. This arguably contributes to the causes of World War Two.

Bridget Kendall asks if we are still haunted by the Treaty of Versailles.