How the World Went to War in 1914


On 28 June 1914, Archduke Franz Ferdinand, the heir to the Austro-Hungarian throne, and his wife were assassinated by a Serbian-backed terrorist. During the crisis that followed, Europe’s leaders made a series of political, diplomatic and military decisions that would turn a localised conflict in south-east Europe into a global war.

Austria-Hungary, with German encouragement, declared war on Serbia on 28 July. Russia’s support of Serbia brought France into the conflict. Germany declared war on Russia on 1 August and France on 3 August. Germany’s violation of Belgian neutrality and British fears of German domination in Europe brought Britain and its empire into the war on 4 August.

These actions reflect the fears, anxieties and ambitions of the European powers. The decisions for war were made in the context of growing nationalism, increased militarism, imperial rivalry and competition for power and influence. Europe’s leaders were willing to go to war to defend or extend national interests and their choices were shaped by a combination of long and short-term foreign policy goals, political pressures at home, previous crises, and the system of opposing alliances that had developed over the previous 35 years.

Archduke Franz Ferdinand and his wife descending the steps of the City Hall, Sarajevo, to their motor car, 28 June 1914.

Archduke Franz Ferdinand and his wife descending the steps of the City Hall, Sarajevo, to their motor car, 28 June 1914.

Relations between Austria-Hungary and neighbouring Serbia had been tense in the years before the murder of the Archduke. Austria had long seen Serbia as a threat to the stability of its multi-ethnic empire. Austria’s annexation of Bosnia in 1908 and Serbian ambitions to unify south-east Europe’s Slavic people further strained relations in this volatile part of Europe. Following the Balkan Wars of 1912-1913, Serbia emerged as a larger and more assertive presence in south-east Europe. On 28 June 1914, a Bosnian-Serb terrorist shot and killed Archduke Franz Ferdinand, heir to the Austrian throne. The assassin was 19-year-old Gavrilo Princip, one of several would-be young assassins who were intent on using violence to destroy Austria-Hungarian rule. Suspecting Serbian backing for the assassination, Austria-Hungary was determined to use the royal murder to crush the Serbian threat once and for all.

Europe takes sides

A cartoon map depicting Europe in 1914.
A cartoon map depicting Europe in 1914.  Cc Imperial War Museum

The crisis which developed in the summer of 1914 was one of several that had erupted in Europe in the early twentieth century. International tensions had been mounting, but in every previous crisis a continental war had been avoided. The assassination of Franz Ferdinand stoked old tensions beyond the Balkans. The crisis spread as other powers pledged support for either Austria or Serbia. Austria knew that conflict with Serbia would likely involve Russia, which saw itself as Serbia’s protector. Austria-Hungary turned to its own ally. On 5 July, Germany promised Austria full support for a severe response against Serbia. Austria-Hungary’s aggression towards Serbia and Russian support for Serbia in the aftermath of the assassination stemmed from fears that, if either backed down, they would lose credibility and prestige as great powers. Germany’s ambitions, its perception of its own isolation and its increasing fear of ‘encirclement’ drove its foreign policy. The preservation of Austria-Hungary – its only reliable ally – as a great power became an important part of German policy.

Britain agonises over its position

A British recruitment poster.
A British recruitment poster.

Britain was largely removed from the growing crisis in Europe until late July. News of the assassination of Franz Ferdinand was met with shock and surprise in Britain, but it was regarded as a distant crisis. As the crisis grew, British involvement remained uncertain, even as the threat of war spread across Europe. Many did not want to fight and believed that Britain should not get involved. The government was divided over Britain’s involvement in what was regarded by some as a purely European affair. It had authority over the military in making final decisions for war – unlike in Germany where the military high command had immense power. Britain’s foreign policy was based upon maintaining a balance of power in Europe. Britain was also determined to protect its vast global empire and its sea trade. It feared Germany’s domination of the continent and its challenge to British industrial and imperial supremacy. But until late July 1914, Britain was largely preoccupied with domestic issues. Social, industrial and political unrest and the threat of civil war in Ireland received most of the nation’s attention.

From 24 July, British Foreign Secretary Sir Edward Grey tried to organise an international peace conference to prevent further escalation. Although France accepted his proposals, Germany refused. On 29 July, Germany requested British neutrality in the event of a European war, which Britain refused. German victory in western Europe would establish its control along the Channel coast and pose a threat to Britain’s security and trade. From 1 August, the British took further action that brought them closer to war. They mobilised the navy and promised to protect the French coast from German aggression through the Channel. On 2 August, the Cabinet agreed to support Belgium if there was a substantial violation of its neutrality.

After declaring war on France, Germany was now determined to execute its war plan to defeat France first and then concentrate its forces against Russia. The plan required German troops invade Belgium to get to France. This would be in direct violation of Belgium’s neutrality, which had been guaranteed in a treaty signed by major European powers, including Britain, in 1839. On the evening of 2 August 1914, Germany demanded that its troops be allowed to pass through Belgian territory. Belgium refused. Accepting Germany’s demands would make Belgium complicit in the attack on France and partially responsible for the violation of its own neutrality. Germany invaded on 4 August.

Germany’s invasion of Belgium tipped the balance for Britain. At 2pm on 4 August, it issued an ultimatum demanding Germany withdraw its troops. At 11pm, the deadline passed without a reply. Britain declared war. Britain’s entry into war was partially a reaction to larger anxieties about the balance of power in Europe, as well as its own security and position in the world. But by violating Belgium’s neutrality, Germany positioned itself as the belligerent aggressor and made British intervention a moral issue about the rights of small nations.

A British recruitment poster.

The entry of Britain and its empire made this a truly global war. Europe’s leaders went to war with the general support of their citizens. This was especially important in Britain, where there was no compulsory military service and recruitment would be dependent on voluntary enlistment.