The assassination of Archduke Francis Ferdinand triggered World War I. However, the war had its origins in developments in the 1800's. The chief causes of World War I were the European Alliances, nationalism, imperialism, and militarism. The alliance system was one of the last factors to emerge before the war. Consequentially, the contributions of this system to the beginning of the Great War have to be considered. Although the alliance system was a main cause of the First World War, it arose because of several other factors, and did not cause the war single handedly. .
Nationalism was the next major long-term cause of WWI. Nationalism involved all those who shared a common language, history and culture. It was a strong feeling of support for one's own nation. Nationalists believed that the needs of their nation were more important than the needs of other nations. Nationalists were so proud of their nation that they wanted it to be the richest and most important - and recognized as such. Such strong feelings made the countries very aggressive towards other nations and quite unforgiving if their nation had been offended. It was nationalism that encouraged Givrilo Princip to shoot dead the Austrian heir. Nationalism greatly blew up the tension and had an influence in causing WWI.
Another cause of WWI was imperialism. Imperialism is the desire of nations to own colonies and form an empire. European countries had been taking over colonies throughout the world since the fifteenth century. From 1870 on there was an unwritten competition to take over parts of the world they had earlier considered not worth colonizing. Britain and France, and Germany and France had almost gone to war over clashes in North Africa. Italy resented France because they prevented the setting up of Italian colonies, and the British and Russians clashed over who should have control in Persia, but were both worried that Germany would take land in the Middle East.