In the ancient Roman calendar, the Ides fell on the 15th day of the months of March, May, July, and October, and on the 13th for the rest of the months. The Romans did not number each day of a month from the first to the last day. Instead, they counted back from three fixed points of the month: the Nones (the 5th or 7th, eight days before the Ides), the Ides, and the Kalends (1st of the following month). The Ides of March, specifically on March 15th, is famous because of the assassination of Julius Caesar in 44 BC.

“Beware the Ides of March” is a famous line from William Shakespeare’s play “Julius Caesar.” In the play, a soothsayer warns Julius Caesar to be cautious on the Ides of March, which is March 15th. It serves as a foreshadowing of the events that ultimately lead to Caesar’s assassination on that day. The phrase is often used to caution someone to be wary of potential dangers or betrayals.

Caesar was stabbed to death at a meeting of the Senate by as many as 60 conspirators, led by Brutus and Cassius. According to ancient historian Plutarch, a seer had warned that harm would come to Caesar on the Ides of March. On his way to the Theatre of Pompey (where he would be assassinated) Caesar passed the seer and joked, “Well, the Ides of March are come”, implying that the prophecy had not been fulfilled, to which the seer replied “Aye, they are come, but they are not gone.”