The historical treaty that ended World War I is the Treaty of Versailles, signed on June 28, 1919. It marked the formal conclusion of the war between the Allied Powers and Germany. The treaty imposed heavy reparations and territorial losses on Germany and aimed to prevent future conflicts by establishing new national boundaries and creating the League of Nations to promote diplomacy. However, the punitive measures of the treaty contributed to significant political and economic instability in Germany, which eventual factors led to the outbreak of World War II. The treaty remains a controversial historical document, reflecting the complexities of post-war diplomacy.