In the late days of June 1914, Archduke Franz Ferdinand of Austria fell victim to an assassination carried out by a Serbian nationalist in Sarajevo, Bosnia. This tragic event set off a chain reaction of escalating threats and mobilization orders, ultimately leading to the outbreak of World War I by mid-August. The war pitted the Central Powers, consisting of Germany, Austria-Hungary, and the Ottoman Empire, against the Allied Powers, which included Great Britain, France, Russia, Italy, and Japan. The United States later joined the Allies in 1917. The four years of the conflict, known as the Great War at the time, witnessed an unprecedented level of devastation and loss of life. The introduction of modern weaponry, such as machine guns, tanks, and chemical weapons, coupled with grueling trench warfare, contributed to the immense carnage. When World War I finally came to an end in November 1918, the Central Powers were defeated, but the cost was staggering. Over 9 million soldiers had lost their lives, and an additional 21 million were left wounded.

Although tensions had been simmering in Europe, particularly in the troubled Balkan region, for several years prior to the outbreak of conflict, the catalyst for the start of World War I occurred in Sarajevo, Bosnia. It was there that Archduke Franz Ferdinand, the nephew of Emperor Franz Josef and the heir to the Austro-Hungarian Empire, was assassinated alongside his wife by the Serbian nationalist Gavrilo Princip on June 28, 1914. This assassination set off a rapid series of events: Austria-Hungary, like many other countries worldwide, held the Serbian government responsible for the attack and saw it as an opportunity to address the issue of Slavic nationalism once and for all. With Russia backing Serbia, Austria-Hungary delayed declaring war until they received assurances from German leader Kaiser Wilhelm II that Germany would support them in the event of Russian intervention, which could potentially involve France, Russia’s ally, and even Great Britain.

On the 5th of July, Kaiser Wilhelm made a secret commitment, providing Austria-Hungary with an unconditional assurance of Germany’s support in the event of war. Austria-Hungary then issued an ultimatum to Serbia, which contained such severe terms that it was nearly impossible for Serbia to accept. Believing that Vienna was preparing for war, the Serbian government ordered the mobilization of its army and sought assistance from Russia. On the 28th of July, Austria-Hungary declared war on Serbia, leading to the collapse of the fragile peace among Europe’s major powers. Within a week, Russia, Belgium, France, Great Britain, and Serbia had formed an alliance against Austria-Hungary and Germany, marking the beginning of World War I.