392 - Roman Emperor Theodosius declares Christian religion, state religion
1889 - Montana admitted as 41st state of the Union
1895 - German physicist Wilhelm Röntgen produces and detects electromagnetic radiation in a wavelength range today known as X-rays or Röntgen rays
1977 - Manolis Andronikos, a Greek Archaeologist and professor at the Aristotle University of Thessaloniki, discovers the tomb of Philip II of Macedon at Vergina.
1980 - Voyager 1 space probe discovers 15th moon of Saturn
