The cause of WW1 was by a Serbian group known as the black hand.On June 28,1914 six black hand members set out to kill Franz Ferdinand.5 of which failed to do so.One member manage injure the escorts of Franz Ferdinand.Afterwards Franz and his wife went to the hospitial to visit these escort and express their gratitude for protect the archduke.Afterwards Franz's driver after they visited the hospitial acciedently made a wrong turn on a street.And you know was on that street, Gavrilo Princip at a cafe.Princip Quickly pull out his gun and shot both Franz and his wife killing them.Afterwards,the Austro-Hunagarian empire was outrage and sent fourth a contract to Serbia saying have to accept all the contracts demands or war would be declared.Serbia chose war,Russia steped in to help the serbians,and france and britian steped in t help russia