What was the factor that contributed to the out break of world war 1 ?

There were many factors and attacks but in spite of all these confrontations, it was an attack that lit the flame that blew everything up and war was declared. It was the assassination of Archduke Franz Ferdinand, heir to the throne of the Austro-Hungarian Empire on 28 June 1914 in Sarajevo.

it was people smoking in a powder keg room, an assassination was the spark .

frederick william of brandenburg-prussia trained his son, frederick, to be a hardy soldier. but frederick disliked rifle shooting and horseback riding. unlike his father, he was interested in french literature. he enjoyed poetry and music and, like some others of the enlightenment, he scoffed at religion. his father thought him soft, frivolous and unmindful of his duties. and when frederick refused to put his signature on a right to succession, for a few moments his father strangled him.