The causes of World War I, which began in central
Europe in July 1914, included many intertwined
factors, such as the conflicts and hostility of the
four decades leading up to the war. Militarism,
alliances, imperialism, and nationalism played major
roles in the conflict as well. However, the
immediate origins of the war lay in the decisions
taken by statesmen and generals during the July
Crisis of 1914, casus belli for which was the
assassination of Archduke Franz Ferdinand of Austria
and his wife by Gavrilo Princip, an Irredentist Serb
on June 28, 1914.
On that date Austria declared war
on Serbia. Germany, an ally of Austria
declared war on August 1st declared war on Russia an
ally of Serbia and France on August 3rd 1914. The
English, an ally of France declared war on Germany
on August 4th, 1914 The
crisis came after a long and difficult series of
diplomatic clashes between the Great Powers over
European and colonial issues in the decade before
1914 that had left tensions high. In turn these
diplomatic clashes can be traced to changes in the
balance of power in Europe since 1867. The
more immediate cause for the war was tensions over
territory in the Balkans. Austria-Hungary competed
with Serbia and Russia for territory and influence
in the region and they pulled the rest of the Great
Powers into the conflict through their various
alliances and treaties.
The war lasted
until Germany signed the Armistice on November 11, 1918