Causes of WWI.

World War 1 was first known as the Great War. They changed the name after World War 2 happened. A major cause of the war was the assassination of Austria-Hungary's Archduke Franz Fernidad. A nationalist murdered him. Also, countries started spending more and more money on their military forces. (Militarism.) Before long, alliances were formed; such as the Three Emporers Lead and the Triple Alliance.

It was basically a chain reaction atfer the assassination of Fernidad. Each country that was allied with another country joined in on the war. Then, almost every major country was active in the war. It was extremley hard to take over another country, mostly because of trenches. After American forces were suddenly attacked, the USA joined the war and helped with the victory of the Triple Alliance.