On June 28, 1919, world leaders gathered at the Palace of Versailles outside Paris, France, to sign the treaty that officially ended World War I.

The war had lasted more than four years and claimed millions of lives. Known at the time as “The Great War,” the conflict involved many of the world’s major powers and left much of Europe damaged, exhausted and grieving.

The Treaty of Versailles placed major responsibility for the war on Germany and required the country to accept strict terms. Germany lost territory, including Alsace-Lorraine, which was returned to France. It also gave up its overseas colonies and was ordered to pay large reparations to the Allied nations.

The treaty also placed limits on Germany’s military. Its army was reduced, and the country was restricted from rebuilding its armed forces in the way it had before the war.

At the time, Allied leaders hoped the treaty would help create a lasting peace. Instead, many Germans viewed the agreement as harsh and humiliating. In the years that followed, Germany faced economic hardship, political unrest and growing resentment over the treaty’s terms.

Historians still debate the long-term effects of the Treaty of Versailles, but many agree it played an important role in shaping the conditions that led to World War II two decades later.

More than a century after it was signed, the Treaty of Versailles remains one of the most important agreements in modern history. It marked the official end of one world war, but it also showed how difficult it can be to build a lasting peace after such enormous loss.