On This Day: World War I Begins

On July 28, 1914, one month to the day after Archduke Franz Ferdinand of Austria and his wife were killed by a Serbian nationalist in Sarajevo, Austria-Hungary declares war on Serbia, effectively beginning the Great War, or, as we now know it; World War I.

In the days following the rest of Europe was drawn into the fight, due to several secret alliances

On August 1 Germany declared war on Russia. Russia’s ally, France, ordered its own general mobilization that same day, and on August 3, France and Germany declared war on each other. The German army’s planned invasion of neutral Belgium, announced on August 4, prompted Britain to declare war on Germany.

Thus, in the summer of 1914, the major powers in the Western world—with the exception of the United States and Italy, both of which declared their neutrality, at least for the time being—flung themselves headlong into World War I.

World War I July 1914 to November 1918. More than 70 million military personnel were mobilized. Over 9 million combatants and 7 million civilians died, including the victims of a number of genocides.

By the end of the war, the German Empire, Russian Empire, Austro-Hungarian Empire and the Ottoman Empire ceased to exist. National borders were redrawn, with several independent nations restored or created, and Germany's colonies were parceled out among the winners. During the Paris Peace Conference of 1919, the Big Four (Britain, France, the United States and Italy) imposed their terms in a series of treaties.