What led to World War I? There are several things that led to World War I. World War I occurred between the year of July 1914 and November 1948. The war actually had several reasons why it was started. Some of the reasons on why World War I was started are: some countries throughout Europe made mutual defense agreements that would cause them to go into battle and imperialism. Imperialism was because of the raw materials the areas could provide which caused them more or less to become greedy and this increased the competition of the countries to confront each other and led them into war. The increase in the military gave Germany and Great Britain the increase they needed to boost their military forces and this helped push the countries to war.
