GCSE History: Causes of World War One Guide

Long-term tensions

By 1914, Europe's major powers were divided into two alliance systems: the Triple Alliance (Germany, Austria-Hungary, Italy) and the Triple Entente (Britain, France, Russia). Militarism (an arms race, particularly a naval race between Britain and Germany) and imperial rivalry also increased tension.

The Balkans

The Balkans were a region of instability, with Austria-Hungary and Russia both seeking influence as the Ottoman Empire weakened. Nationalist movements, particularly in Serbia, added to the tension.

The assassination and July Crisis

The assassination of Archduke Franz Ferdinand of Austria-Hungary by a Serbian nationalist in Sarajevo in June 1914 triggered a diplomatic crisis. Austria-Hungary issued an ultimatum to Serbia, and the alliance system drew in the other major powers within weeks.

Why war spread so quickly

Because of the alliance system, a regional conflict between Austria-Hungary and Serbia escalated rapidly, as Russia mobilised to support Serbia, Germany declared war on Russia and France, and Britain entered after Germany invaded neutral Belgium.

Common mistakes

• Treating the assassination as the sole cause, rather than the trigger for existing tensions.
• Mixing up which countries belonged to the Triple Alliance and Triple Entente.
• Forgetting Britain's specific reason for entering the war (the invasion of Belgium).