The Ides of March is the day on the Roman calendar marked as the Idus, roughly the midpoint of a month, of Martius, corresponding to 15 March on the Gregorian calendar. It was marked by several major religious observances. 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.

 

In modern times, the Ides of March is best known as the date on which Julius Caesar was assassinated in 44 BC. Caesar was stabbed to death at a meeting of the Senate. As many as 60 conspirators, led by Brutus and Cassius, were involved. According to 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." This meeting is famously dramatised in William Shakespeare's play Julius Caesar, when Caesar is warned by the soothsayer to "beware the Ides of March." The Roman biographer Suetonius identifies the "seer" as a haruspex named Spurinna.

 

Caesar's assassination opened the final chapter in the crisis of the Roman Republic. After his victory in Caesar's civil war, his death triggered a series of further Roman civil wars that would finally result in the rise to sole power of his adopted heir Octavian. In 27 BC, Octavian became emperor Augustus, and thus he finally terminated the Roman Republic. Writing under Augustus, Ovid portrays the murder as a sacrilege, since Caesar was also the pontifex maximus of Rome and a priest of Vesta.  On the fourth anniversary of Caesar's death in 40 BC, after achieving a victory at the siege of Perugia, Octavian executed 300 senators and equites who had fought against him under Lucius Antonius, the brother of Mark Antony. The executions were one of a series of actions taken by Octavian to avenge Caesar's death. Suetonius and the historian Cassius Dio characterised the slaughter as a religious sacrifice, noting that it occurred on the Ides of March at the new altar to the deified Julius.