WORLD WAR ONE IT WAS ON SARAJEVO BOSNIA,JUNE 28,1914 WHILE ARCHDUKE FRANZ FERDINAND WAS ROAMING AROUND WITH HIS WIFE SOPHIE,THEY WERE KILLED BY A BLACK HAND 19 YEAR OLD BOY,NAMED GAVRILO PRINCIP.FRANZ FERDINAND IS A HEIR OF AUSTRIA-HUNGARY,AUSTRIA-HUNGARY WAS ANGRY ON WHAT HAPPENED TO THEIR HEIR.ON JULY 28,1914 THEY DECLARED WAR TO SERBIA.RUSSIA OFFERS HELP TO SERBIA WHILE GERMANY HELPS THE AUSTRIA-HUNGARY.