Caesar: The ides of March are come.
Soothsayer: Aye, Caesar, but not gone.
—Julius Caesar, Act III, Scene 1

Thanks to Shakespeare's indelible dramatization, March 15—also called the Ides of March—is forever linked with the 44 B.C. assassination of Julius Caesar, and with prophecies of doom.

"That line of the soothsayer, 'Beware the ides of March,' is a pithy line, and people remember it, even if they don't know why," said Georgianna Ziegler, head of reference at Washington, D.C.'s Folger Shakespeare Library.

Until that day Julius Caesar ruled Rome. The traditional Republican government had been supplanted by a temporary dictatorship, one that Caesar very much wished to make permanent.

But Caesar's quest for power spawned a conspiracy to have him killed, and on the Ides of March, a group of prominent Romans brought him to an untimely end in the Senate House....