'The Ides of March' is a fancy way of saying 'March 15th,' but what does it mean and why is it important? Here is a break down: The 15th of March is a famous date because it was the day that Julius Caesar was assassinated. Prior to his death, Caesar was warned by a soothsayer to beware March 15th but he ignored the warning. William Shakespeare then popularized the line in his play, 'Julius Caesar,' by having the soothsayer tell Caesar: "Beware the Ides of March." Though Shakespeare's line is fiction, history says that a soothsayer did actually warn Caesar to beware the middle of the month. The term "Ides" comes from the Latin word "idus," a plural word that refers to a date that falls in the middle of each month, generally following the cycle of the moon.