Assassination

The general cause of World War 1 was assassination. Archduke Franz Ferdinand was meant to become king of Austria-Hungary but was murdered by a guy named Gavrilo Princip, which was a member of "The Black Hand" which is a Serbia group which had planned the killing. Austria-Hungary threatened Serbia to go to war because of the assassination. The agreements with each country meant that Germany had to side with Austrian-Hungary while Russia had to side with Serbia. On July 28th, 1914, Austria-Hungary declared war on Serbia. Then Germany declared war on Russia, and on August 3rd they declared war on France. Once Germany marched into war with France on August 4th, Britain joined the war soon after.