World one started because the assassination of Francesca Duke of Austria-Hungarian> Germany declared war on Serbia then Russia said no no no and declared war on Germany and then bam WW1
<em>The first world war began in August 1914. It was directly triggered by the assassination of the Austrian archduke, Franz Ferdinand and his wife, on 28th June 1914 by Bosnian revolutionary, Gavrilo Princip. This event was, however, simply the trigger that set off declarations of war.</em>
<em>* Hopefully this helps:) Mark me the brainliest :) !!!!</em>
