The Ides of March (/aɪdz/; Latin: Idus Martiae, Late Latin: Idus Martii) is a day on the Roman calendar that corresponds to 15 March. … In 44 BC, it became notorious as the date of the assassination of Julius Caesar which made the Ides of March a turning point in Roman history.
The Romans considered the Ides of March as a deadline for settling debts. But – for our modern world – if you‘ve heard of the Ides of March, it’s probably thanks to William Shakespeare. In his play Julius Caesar, a soothsayer attracts Caesar’s attention and tells him: Beware the ides of March.
Jules Caesar by Shakespeare
Who is it in the press that calls on me?
I hear a tongue shriller than all the music
Cry “Caesar!” Speak, Caesar is turn’d to hear.
Beware the ides of March.
What man is that?
A soothsayer bids you beware the ides of March.
Julius Caesar Act 1, scene 2, 15–19
The importance of the ides of March for Caesar is that it is the day he will be assassinated by a group of conspirators, including Brutus and Cassius. Despite numerous and improbable portents—the soothsayer’s warning, some fearsome thundering, his wife’s dreams of his murder, and so on—Caesar ventures forth on the ides to meet his doom.
Shakespeare borrowed this scene, along with other details of Caesar’s demise, from Plutarch’s Life of Julius Caesar. An English translation was readily available, but its precise phrasings weren’t quite dramatic enough for Shakespeare’s purposes. Where he has the soothsayer declaim, “Beware the Ides of March,” the more prosaic original notes merely that the soothsayer warns Caesar “to take heed of the day of the Ides of March.”