1920-Francis G. Pease's interferometer at Mount Wilson Observatory is the first to measure the diameter of a star - the Betelgeuse
1937-Japanese troops conquer and plunder Nanjing (Nanjing Massacre)
1979-Saudi Arabia raises marker crude price to $24 per barrel
1979-Strikes against price increases in Gda?sk, Poland
1981-Poland's authoritarian communist government declares martial law and arrests Solidarity activists in a failed attempt to crush the opposition
1981-Polish communist government jails former communist party leader Edward Gierek
1982-Earthquake hits Northern Yemen; 2,000 die
1991-Both North and South Korea sign an accord calling for reconciliation
2002-The European Union announces that Cyprus, the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Malta, Poland, Slovakia and Slovenia will become members from May 1, 2004