The significant global conflict that reshaped the political landscape of Europe is World War I, which lasted from 1914 to 1918. This catastrophic war involved numerous countries and alliances, with immense human and economic tolls. The aftermath of World War I resulted in significant territorial changes, the dismantling of empires like Austria-Hungary and the Ottoman Empire, and the establishment of new nations. The Treaty of Versailles formally ended the war and imposed heavy reparations on Germany, sowing the seeds of economic and political instability that would eventually contribute to the rise of World War II.