World War I was the first World War it was horrible and wasn't as bad as World War II but was Horrible too. About 7 million civilians were killed it all started with the assassination of Franz Ferdinand the heir to the throne of the Austro-Hungarian the Serbians assassinated him and it was their fault within weeks War had started Germany, Austria-Hungary, and the Ottoman Empire allied themselves as the Central Powers. Serbia, France, Russia, England, Italy, Belgium, Japan, Portugal allied themselves as the Allied Powers. America, Greece, and Siam joined later in 1917. America joined in because the Germans were sinking their ships, and that Russia had backed out of the war. In all the war lasted four years and was very bad.