The war began on July 28, 1914, following the assassination of Archduke Franz Ferdinand of Austria.
It was initially called the 'Great War' and only became known as the First World War after the Second World War began.
Over 70 million military personnel, including 60 million Europeans, were mobilized during the war.
Trench warfare was a common feature of the war, with soldiers living in deep trenches for months.
The war saw the introduction of new weapons such as tanks, machine guns, and chemical weapons like mustard gas.
The Battle of the Somme, one of the largest battles of the war, resulted in over one million casualties.
The Christmas Truce of 1914 saw soldiers from both sides emerge from their trenches to exchange greetings and play football.
The United States entered the war in 1917, providing fresh troops and resources that helped turn the tide in favor of the Allies.
The First World War led to the collapse of four empires: the Austro-Hungarian, Ottoman, German, and Russian Empires.
The Treaty of Versailles, signed in 1919, officially ended the war and imposed heavy reparations on Germany.
World War I was one of the deadliest conflicts in history, with an estimated 16 million deaths and 21 million wounded.
The war significantly advanced medical and technological innovations, including the development of plastic surgery and blood transfusions.
The term 'shell shock' was coined during the war to describe the psychological trauma experienced by soldiers.
Women played a crucial role in the war effort, working in factories, serving as nurses, and taking on jobs traditionally held by men.
The First World War set the stage for major political changes and the eventual outbreak of the Second World War in 1939.
