- 44 BC- Julius Caesar is stabbed to death by Roman senators. ("Et tu, Brute?")
- 1493 - Christopher Columbus returns to Spain after finding the Americas and giving all sorts of deadly diseases to the natives they found.
- 1545 - The first Council of Trent
- 1572 - Charles II of England issues Royal Declaration of Indulgence, basically suspending punishments on people who didn't want to attend the Church of England. (But Parliament wasn't too excited about this. They thought he was secretly a Roman Catholic, so they made him undo it.)
- 1776 - South Carolina is officially a badass. They're the first colony to declare independence from England.
- 1917 - Tsar Nicholas II of Russia abdicates his throne, and his brother becomes the Tsar. But the damage was done for the Romanovs. The monarchy fell anyway, due to the revolution happening. Nicholas' entire family was executed the next year.
- 1939 - Hitler and his army occupies the rest of Bohemia and Moravia. Czechoslovakia doesn't exist anymore.
- 1956 - My Fair Lady premiers on Broadway!
- 1985 - The first internet domain name is registered!
- 1990 - Mikhail Gorbachev is elected the first President of the Soviet Union.
- 2004 - French President Jacques Chirac passes a law which bans wearing conspicuous religious symbols in French public schools. It's commonly known as "the headscarf ban."
- 2005 - The International Criminal Court hears its first case, allegations of war crimes which occurred during civil war in the Congo.
- 2006 - An online magazine, salon.com publishes the most extensive documentation of the Abu Ghraib prisoner abuse.
- 2008 - Unrest in Tibet continues. The Tibet Autonomous Region gives the protesters until March 17 to surrender.
Being the terrible researcher I am, I found all this information from Wikipedia. (Ok, so I embellished a little.) Lots more stuff happened on March 15th; this is just the mildly exciting stuff.
Beware the Ides of March!