Question

when was the first world war?
what is the main reason of first world war?

Answer 1

july 1914 to   November  1918 
war was the result of greed of Austria and Germany to expand their region.

Answer 2

1st world war was held from 28 july 1914- 11 november 1918. the main reason of 1st world war was the rivalry between austria hungary on one side and russia ,france and great britain on the other side. the factors responsible for the conflict were political ,territorial and economic ,militarism,a complex web of alignments and alliances, imperialism,growth of nationalism and the power vaccum created by the decline of ottoman empire.other factors are also taken into consideration like territorial disputes,t he perceive breakdown of power balance of europe,convuleted and fragmented governance,t he arms races of previous decades and military planning.