What started world war 1?
officially the assassination of Archduke Ferdinand of the Austro-Hungarian empire started WWI.However, it was really caused by contest between the powers of Europe and a tangle of alliances. The killing of Archduke lead Austria-Hungary to invade Serbia, which was where the assassin was from. This caused Russia to come to Serbia’s aid. Germany then declared war on Russia to back up its ally, A-H. France then declared war on A-H and Germany to back up its ally, Russia. England then declared war to back up its allies, France and Russia. Later, the US joined the war in response to the sinking of the Lusitania and the fact that Germany had promised Mexico land if they declared war on the US to keep them out of the war in Europe. Italy joined the allies in a quest for land. the Ottoman empire joined the Central powers to fight Russia. As you can see one ally pulled another in and it just turned into a World war.
