Causes of World War I

The political, military, economic, and diplomatic factors that led to the outbreak of World War I in 1914. The assassination of Archduke Franz Ferdinand triggered a crisis that turned these tensions into war.

Assassination of Archduke Franz Ferdinand: The June 28, 1914, killing of Austro-Hungarian heir Franz Ferdinand and his wife Sophie in Sarajevo by Gavrilo Princip. The assassination triggered the diplomatic crisis that converted existing tensions into war.
Alliance system before World War I: The network of treaties and diplomatic alignments among European powers before 1914. Alliances shaped expectations of support and widened the consequences of the crisis.
Gavrilo Princip: A Bosnian Serb nationalist who assassinated Archduke Franz Ferdinand and Sophie in Sarajevo in 1914. His attack supplied the immediate pretext for Austria-Hungary’s confrontation with Serbia.
War guilt question: The historical debate over responsibility for the outbreak of World War I and the meaning of Article 231 of the Treaty of Versailles. It turns explanations of the causes into a question of responsibility and blame.
World War I: A global war fought from 1914 to 1918, primarily between the Allied Powers and the Central Powers. It was the conflict produced by the interacting causes and the July Crisis.
July Crisis: The sequence of diplomatic and military decisions in July 1914 that followed the Sarajevo assassination and led to war. It traces the immediate escalation from Austria-Hungary’s demands to declarations of war.
Militarism: The elevation of military power, preparedness, and armed forces in political life. Arms competition and military planning made threats harder to contain.
Franz Joseph I of Austria: Emperor of Austria and king of Hungary from 1848 until his death in 1916. His government chose a forceful response to the assassination amid imperial insecurity.
Fischer thesis: The interpretation, associated with historian Fritz Fischer, that German leaders pursued expansionist aims and bore major responsibility for the war. It challenges accounts that treat the conflict as an unintended result of shared tensions.
Invasion of Belgium (1914): Germany’s invasion of neutral Belgium in August 1914 during its attack on France. The invasion brought Britain into the war and widened the conflict.

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Archduke Franz Ferdinand of AustriaRelated: His assassination was the immediate trigger, while deeper rivalries shaped the war that followed.