World War I was a global conflict that lasted from July 28, 1914, to November 11, 1918, involving major world powers divided into the Allies and Central Powers, with Germany being a key player. Prior to the war, Germany, under Otto von Bismarck, sought alliances for defense but faced increasing isolation after his dismissal, leading to tensions with neighboring nations. The conflict escalated rapidly after the assassination of Archduke Ferdinand, culminating in a series of declarations of war that involved multiple countries.