On July 28, 1914, Europe was rocked by the outbreak of the First World War. On November 11, 1918, the First World War ended after four long years of fighting. This conflict was both the longest and one of the biggest in the history of warfare.
More than 70 million people, including 60 million Europeans, served in the military. This war was also very lethal, with around 9 million military members and 7 million civilians dying.
The murder of Archduke Franz Ferdinand by Gavrilo Princip set off the Great War. Serbia and Austria-Hungary went to war after the murder. A tangle of relationships fueled the escalation of the conflict. The Triple Entente and the Triple Alliance fought each other for control of Europe.
A chain reaction ensued. Russia was prepared to protect Serbia, its ally. Then, to preserve Austria, Germany declared war on Russia. To save Russia, France went to war with Germany. After Germany invaded Belgium, the United Kingdom declared war on Germany.
Also See: Axis Powers
On the one hand, Austria-Hungary, Bulgaria, Germany, and the Ottoman Empire were all parties to this conflict. France, Great Britain, Italy, Japan, Romania, Russia, and the United States fought against them. In 1917, the Treaty of Versailles was signed, bringing an end to World War I.