The "Great War," commonly known as World War I, occurred from 1914 to 1918 and involved many of the world's great powers. It was primarily fought between two major alliances: the Allies, which included countries like France, Britain, and Russia, and the Central Powers, led by Germany, Austria-Hungary, and Ottoman Empire. The war was marked by trench warfare and significant battles, resulting in millions of military and civilian casualties. The conflict was triggered by the assassination of Archduke Franz Ferdinand of Austria-Hungary in June 1914. It led to widespread mobilization and a series of political alliances that escalated the situation. The war ended with the signing of the Treaty of Versailles in 1919, which imposed heavy reparations on Germany and redrew national boundaries, setting the stage for future conflicts.