20th Century 1914-1918. World War I June 28, 1914 Assassination of Archduke Ferdinand of Austria. (austria hungary) By serbian rebel … of the terrorist group Blackhand. By August 10th 1914. Russia, France, england vs austria - hungary, germany & ottoman. The Great War. 1929 - Great depression 1933 - Japan invades manchuria 1939 - Sept 1, Hitler invades poland. 1939 - World War 2 1945 - 1991 - Cold War 1940 - 1980s - Colonies gain independence.