First World War E01 Why Did WWI Start?

In July 1914, Europe stood at the edge of what its rulers believed would be a short and routine conflict. The German and Russian Empires prepared for war with optimism, assuming victory would come within weeks. German Emperor Kaiser Wilhelm II famously told his soldiers they would return home before the leaves fell from the trees. Russian commanders shared similar confidence.

What none of them foresaw was that this “short war” would last 1,566 days, claim millions of lives, and permanently alter world history. This conflict would first be called The Great War and later remembered as World War I (WWI).

The Sarajevo Assassination: The Spark That Ignited the Great War

On June 28, 1914, an open-roof car emerged from the town hall in Sarajevo, the capital of Bosnia. Inside were Archduke Franz Ferdinand, heir to the Austro-Hungarian throne, and his wife Sophie, Duchess of Hohenberg. Sitting beside the driver was Bosnia’s military governor, Oskar Potiorek.

Earlier that morning, a bomb had been thrown at the Archduke’s car but narrowly missed. While traveling to visit the injured companions at a hospital, the driver took a wrong turn and slowed down to correct the route. At that moment, a 19-year-old Bosnian Serb student, Gavrilo Princip, fired two shots. One bullet pierced Franz Ferdinand’s neck, the other struck Sophie in the abdomen. Within minutes, both were dead.

This assassination was not merely the murder of two individuals—it was the event that triggered the most devastating war the world had ever seen.

Europe Before the War: Empires and Ethnic Tensions

In 1914, Europe was dominated by four major empires:

The Russian Empire

The Ottoman Empire

The Austro-Hungarian Empire

The German Empire

Central and Eastern Europe were either directly ruled by these empires or divided into smaller states. Austria-Hungary, the largest empire in Central Europe, ruled over many ethnic groups, including Slavic populations.

Serbia, a newly independent state, aimed to unite all South Slavic peoples into a single nation known as Yugoslavia. Bosnia, under Austro-Hungarian control, became Serbia’s primary target. Serbian nationalist groups such as the Black Hand and Young Bosnia, supported by elements of Serbian intelligence, worked underground to weaken Austrian rule. Gavrilo Princip was part of this movement.

Military Alliances: Why a Local Conflict Became a World War

By 1914, Europe was divided into two powerful military blocs:

Triple Entente

Britain

France

Russia

Triple Alliance

Germany

Austria-Hungary

Italy (later remained neutral)

These alliances meant that a war between two nations would inevitably involve all their allies. As political cartoons of the time predicted, if Austria attacked Serbia, Russia would intervene, Germany would support Austria, and Britain and France would be drawn in as well. A regional conflict was destined to become a global war.

Austria’s Ultimatum and the Outbreak of War

On July 23, 1914, Austria-Hungary delivered a harsh ultimatum to Serbia, demanding:

Punishment of those involved in the assassination

Suppression of anti-Austrian organizations

An end to propaganda against Austria

Serbia responded cautiously, accepting most but not all demands. Austria rejected the reply and on July 28, 1914, declared war on Serbia.

Events moved rapidly:

Germany declared war on Russia (August 1)

Germany declared war on France (August 3)

Britain declared war on Germany (August 4)

Within one week, nearly all of Europe was engulfed in war.

Serbia’s Unexpected Resistance

Austria expected a quick victory over Serbia, but under the leadership of Field Marshal Radomir Putnik, the Serbian army fought fiercely. Despite being outnumbered, Serbia defeated Austria in the Battle of Cer and later in the Battle of Kolubara, inflicting heavy casualties.

These humiliating defeats shattered Austria’s image as a great power and forced it to seek greater German support.

Germany’s Schlieffen Plan and Its Failure

Germany’s strategy for a swift victory was the Schlieffen Plan, which aimed to defeat France within 40 days by advancing through Belgium and capturing Paris. France would then be crushed before Russia could fully mobilize.

However, the plan faced critical problems:

Belgium resisted German invasion

Britain entered the war to defend Belgian neutrality

Slow troop movement and logistical challenges delayed the German advance

During the First Battle of the Marne, Allied forces exploited gaps in German lines and halted their progress just 40 kilometers from Paris. The German army retreated and dug defensive trenches along the River Aisne.

The dream of a quick German victory collapsed.

Trench Warfare: A War of Attrition

By the end of 1914, a continuous line of trenches stretched from the North Sea to Switzerland, marking the Western Front. For the next four years, soldiers lived and died in muddy trenches under constant shelling.

Millions were killed, yet neither side could achieve a decisive breakthrough. The war became one of attrition, destroying lives, economies, and empires.

Conclusion: From False Hope to Global Catastrophe

World War I began with overconfidence and miscalculation. What emperors believed would be a brief conflict turned into the deadliest war the world had ever known. The assassination in Sarajevo silenced a relatively peace-minded heir and unleashed a chain reaction of alliances, ultimatums, and invasions.

By the winter of 1914, as leaves fell from the trees, soldiers realized they were far from home—and would remain so for years. The Great War had entered a new, darker phase, one that would reshape the modern world forever.