Beware the ides of March!
March 15 doesn't mean much to us anymore these days, but it has major significance in ancient history.
Supposedly, Roman leader Julius Caesar was warned that something bad was going to happen to him on or around March 15 (hence Shakepeare's "Beware the Ides of March" line in his play, Julius Caesar). A lot of good that warning did. On March 15, 44 B.C., the famed leader was stabbed 23 time in the Roman Senate in a conspiracy led by Marcus Junius Brutus and Gaius Cassius Longinus. There were 60 other conspirators, as well. Sheesh. Caesar had some serious enemies, yo.
On a more fabulous note, Rolls-Royce was incorporated on March 15, 1906.
Beware the sweet rIdes of March.