The First World War, also known as the Great War, was a global conflict that lasted from 1914 to 1918. It involved many of the world's great powers, divided into two main alliances: the Allies and the Central Powers. The war was marked by significant battles, trench warfare, and the use of new military technologies. The war resulted in an estimated 16 million deaths and led to major political changes, including the collapse of empires such as the Austro-Hungarian Empire and the Ottoman Empire. The Treaty of Versailles officially ended the conflict in 1919, setting the stage for future geopolitical tensions.