180: 6 inhabitants of Carthage, North Africa executed for being Christians. Earliest record of Christianity in this part of the world.

1203: Siege of Constantinople begins during the fourth Crusade, Crusaders aboad a Venetian fleet attack the city

1762: Catherine II becomes tsarina of Russia following the murder of Peter III

1918: The Romanov royal family and several of their retainers are executed by a Bolshevik firing squad in the basement of Ipatiev House, in Yekaterinburg, Siberia

1936: Spanish generals Francisco Franco and Emilio Mola lead a right-wing uprising, starting the Spanish Civil War

1945: Potsdam Conference: Harry Truman, Joseph Stalin and Winston Churchill hold 1st post-World War II meeting

2014: Malaysia Airlines Flight 17 is shot down over Eastern Ukraine by a Buk surface-to-air missile launched from pro-Russian separatist-controlled territory, killing all 283 passengers and 15 crew on board

Source: Onthisday.com