The conflict often referred to as "The Great War" before World War II is World War I. This war, which lasted from 1914 to 1918, involved many of the world's great powers, divided into two main alliances: the Allies and the Central Powers. World War I was characterized by trench warfare, significant military innovation, and large-scale battles resulting in immense loss of life. The war ended with the signing of the Treaty of Versailles, which imposed harsh penalties on Germany and attempted to restructure the geopolitical landscape of Europe. The unresolved issues from this conflict ultimately set the stage for World War II.