In late June of 1914, the archduke and heir to the throne of Austria-Hungary was assassinated by a Serbian nationalist. This event is often regarded as the catalyst for the outbreak of World War I. After the archduke’s death, Austria-Hungary, with Germany’s backing, issued an ultimatum to Serbia containing a list of ten demands. These demands included the suppression of rhetoric and media that displayed contempt for the Austro-Hungarian monarchy, the dissolution of Serbian nationalist organizations, and the removal of administration and military officials who were involved in anti-Austrian activities. Serbia was willing to comply with most of the demands, but not all, and it refused to participate in a full investigation into the archduke’s assassination. This refusal became a point of contention between the two nations, ultimately leading Austria-Hungary to declare war on Serbia on July 28, 1914, which marked the official start of World War I.

The conflict quickly escalated beyond just Austria-Hungary and Serbia due to a complex web of alliances. When Austria-Hungary officially declared war, Russia began mobilizing its troops in support of its ally, Serbia. In response, Germany took action on behalf of Austria-Hungary and subsequently declared war on Russia. This conflict further expanded when Germany declared war on France, as France was also an ally of Russia. The situation intensified when Germany invaded Belgium, prompting Great Britain to officially enter the war. Within just a few months of these declarations, much of Europe was already engulfed in the conflict.

The World War I conflict lasted for four years, concluding in 1918. An armistice was signed on November 11, 1918, between Germany and the Allied powers, which brought an end to much of the fighting; however, it did not constitute a formal surrender by Germany. The official end of the war was marked by the signing of peace treaties, including the Treaty of Versailles. While the Treaty of Versailles may have ended World War I, hostilities and tensions persisted in Europe. The treaty imposed harsh penalties on Germany, contributing to instability in the region. These tensions eventually escalated, leading to even greater conflicts.