P: World War I began in 1914, after the assassination of Archduke Franz Ferdinand, and lasted until 1918.
Q: Thanks to new military technologies and the horrors of trench warfare, World War I saw unprecedented levels of carnage and destruction.
R: During the conflict, Germany, Austria-Hungary, Bulgaria and the Ottoman Empire (the Central Powers) fought against Great Britain, France, Russia, Italy, Romania, Japan and the United States (the Allied Powers).
S: By the time the war was over and the Allied Powers claimed victory, more than 16 million people - soldiers and civilians alike - were dead.