World war 1 was one of the most devastating wars in history. The War Occurred Mostly Europe and started in 1914 and ended in 1918. During the First World War, the amount of casualties was devastating. 17 million people died and 20 million wounded. This war is considered to have been a tragedy for many people in Europe as they have never witnessed a war like this before. People believe that the main cause of World War 1 was the assassination of the heir of Austria-Hungary Arch-Duke Franz Ferdinand. However, I believe there’s more to it. There were many other contributions that led to the outbreak of the First World War. In this essay, I’m going to explain why the causes of world war were militarism, imperialism, nationalism, secret alliances, and the assassination of the Arch-Duke Franz Ferdinand. The most Significant of the causes of World War one had to be the secret alliance system that was in place prior to the start of the war. By the start of the 20th century, Europe found itself and separated into two sides. On one side, we have the Triple Alliance, which included Germany, Austria-Hungary, and Italy. In the opposite side of the Triple Alliance was the Triple Entente which consisted of Great Britain, France, and Russia. But later on, Italy joins the Triple Entente when they sign a treat “On her part, Italy undertakes to use her entire resources for the purpose of waging war jointly with France, Great Britain, and Russia against all their enemies.”(Treaty of London,