Assassination of archduke Ferdinand and the invasion of poland
Tang Dynasty was able to strengthen China thru the efforts of its Tang Taizong and Empress Wu in which the former brought back China's government and the latter empowered women. The Song dynasty continued the good governance and elevated the military system thru systematized testing.
with a bigger and better prussian army and in 3 shot wars first against (denmark) second against (austria) and third against (france) he established prussian leadership among the german state