1 The Assassination of Archduke Franz Ferdinand
On June 28, 1914, Archduke Franz Ferdinand, heir to the Austro-Hungarian throne, and his wife Sophie were assassinated in Sarajevo by Gavrilo Princip, a Bosnian Serb nationalist affiliated with the group known as the Black Hand.
This assassination was the immediate trigger for the war. Austria-Hungary saw it as a direct attack on its sovereignty and a threat from Serbian nationalism. The empire, backed by Germany, issued an ultimatum to Serbia with harsh demands. Serbia’s partial rejection led Austria-Hungary to declare war on Serbia on July 28, 1914.
2 The July Crisis
Following the assassination, a tense diplomatic period known as the July Crisis unfolded. The powers scrambled to either deter or prepare for war. Germany gave Austria-Hungary a "blank cheque," promising unconditional support.
Russia mobilized to protect Serbia, which alarmed Germany and Austria-Hungary. France, allied with Russia, began to prepare for conflict, and Britain, initially reluctant, was drawn in by treaty obligations and the threat to Belgium’s neutrality.
3 Mobilization and Declarations of War
The complex system of mobilization plans meant that once one country began mobilizing troops, others had to follow suit quickly or risk strategic disadvantage. Russia’s mobilization prompted Germany to declare war on Russia on August 1, 1914.
Germany then declared war on France on August 3 and invaded Belgium to outflank French defenses. Britain declared war on Germany on August 4, 1914, after Germany violated Belgian neutrality. shutdown123