Austria Declares War on Serbia: World War I Begins

Austria-Hungary declared war on Serbia on July 28, 1914, firing the first shots of a conflict that would kill seventeen million people, destroy four empires, and reshape every border in Europe. What began as a regional dispute over a political assassination became the catastrophe that defined the twentieth century. One month earlier, Gavrilo Princip, a nineteen-year-old Bosnian Serb nationalist, had assassinated Archduke Franz Ferdinand, heir to the Austro-Hungarian throne, and his wife Sophie during a state visit to Sarajevo. Austria-Hungary, determined to crush Serbian-backed nationalism in the Balkans, drafted an ultimatum deliberately designed to be unacceptable. Serbia agreed to nearly all the demands but balked at allowing Austrian officials to conduct investigations on Serbian soil, a condition that would have effectively ended Serbian sovereignty. The declaration of war set off a cascade of treaty obligations and mobilization orders that no government could control. Russia began mobilizing to defend its Serbian ally. Germany, bound by treaty to Austria-Hungary, declared war on Russia and then on France. When German armies violated Belgian neutrality to execute the Schlieffen Plan, Britain entered the war. Within a week, most of the major powers of Europe were at war. Belgrade, the Serbian capital, came under Austrian artillery bombardment on July 29, the day after the declaration. The small Serbian army, battle-hardened from the Balkan Wars, initially repelled the invasion and inflicted humiliating defeats on the Austro-Hungarian forces. Serbia would not be conquered until 1915, when Bulgaria joined the Central Powers and attacked from the east. The war that Austria-Hungary started to preserve its empire instead destroyed it. By November 1918, Austria-Hungary, the Ottoman Empire, the Russian Empire, and the German Empire had all ceased to exist, replaced by a patchwork of new nations and a peace settlement so punitive that it guaranteed another world war within a generation.