World War I was known as "The Great War" before the onset of World War II. It lasted from 1914 to 1918 and involved many of the world’s great powers, divided into the Allies and the Central Powers. The conflict resulted in unprecedented devastation and significant geopolitical changes, leading to the collapse of empires such as the Austro-Hungarian and Ottoman empires. Additionally, the Treaty of Versailles, which officially ended the war, imposed heavy reparations on Germany and is often cited as a contributing factor to World War II. The war left an indelible mark on global history, shaping the 20th century.