World War 1 occurred between July 1914 and November 11, 1918. By the end of the war, over 17 million people would be killed including over 100,000 American troops. The immediate cause of World War I was the assassination of Archduke Franz Ferdinand Austria Hungary. In June 1914, a Serbian nationalist terrorist group called the Black Hand sent groups to assassinate the Archduke. Their first attempt failed when a driver avoided a grenade thrown at their car. Later that day a Serbian nationalist named Gavrilo Princip assassinated him and his wife while they were in Sarajevo, Bosnia which was part of Austria Hungary. This was in protest to Austria Hungary having control of this region. Serbia wanted to take over Bosnia and Herzegovina . This assassination led to Austria Hungary declaring war on Serbia. Russia began to mobalize to help Serbia in the fight but doing so Germany declared war on Russia. As the countries declared war this began and evolved into a war with mutual defense alliances and leading to militarism, alliances, imperialism, nationalism, for short M.A.I.N. the war was givin the name The Great War, The First World War, WWI