The Balkans had been an area of conflict and tension between various ethnic and religious groups for centuries, due to the fact that the region was under the control of the Austro-Hungarian Empire. The emergence of nationalist movements and the desire for independence among Balkan nations created an unstable political environment.
2. Assassination of Archduke Franz Ferdinand
Archduke Franz Ferdinand, heir to the throne of the Austro-Hungarian Empire, and his wife Sophie, were assassinated on June 28, 1914, in the Bosnian city of Sarajevo. The assassin, Gavrilo Princip, was a Bosnian Serb nationalist who sought to free Bosnia and Herzegovina from Austrian control.
3. Diplomatic crisis
After the assassination, Austria-Hungary decided to take action against Serbia, which it believed had supported and provided arms to Princip and other conspirators. Austria-Hungary issued a harsh ultimatum to Serbia, demanding an apology and punishment for those involved in the plot. Serbia accepted most of the demands but rejected others, leading to the declaration of war by Austria-Hungary on July 28, 1914.
4. Alliance system and outbreak of war
The assassination of Archduke Franz Ferdinand ignited the existing tensions in Europe due to the entangled system of alliances between the European powers. Serbia had the backing of Russia, which came to its aid after Austria-Hungary declared war. France, an ally of Russia, pledged support for both Russia and Serbia. Germany, on the other hand, was an ally of Austria-Hungary and came to its defense. Thus, the assassination triggered a chain reaction of mobilization of armies and declarations of war, eventually leading to the outbreak of World War I on August 1, 1914.