The Ides of March (Latin: Idus Martiae, Late Latin: Idus Martii) is a day on the Roman calendar that corresponds to March 15. It was marked by several religious observances and was the date of the assassination of Julius Caesar in 44 BC. The death of Caesar made the Ides of March a turning point in Roman history, as one of the events that marked the transition from the historical period known as the Roman Republic to the Roman Empire.
Although March (Martius) was the third month of the Julian calendar, in the oldest Roman calendar it was the first month of the year. The Romans did not number days of a month sequentially from the first through the last day. Instead, they counted back from three fixed points of the month: the Nones (5th or 7th, depending on the length of the month), the Ides (13th or 15th), and the Kalends (1st of the following month). The Ides occurred near the midpoint, on the 13th for most months, but on the 15th for March, May, July, and October. The Ides were supposed to be determined by the full moon, reflecting the lunar origin of the Roman calendar.
The Ides of each month were sacred to Jupiter, the Romans’ supreme deity. The Flamen Dialis, Jupiter’s high priest, led the “Ides sheep” (ovis Idulius) in procession along the Via Sacra to the arx, where it was sacrificed. The Ides of March was also the occasion of the Feast of Anna Perenna, a goddess of the year (Latin annus) whose festival originally concluded the ceremonies of the new year. The day was enthusiastically celebrated among the common people with picnics, drinking, and revelry. Mamuralia may also have taken place on the Ides of March.
In the later Imperial period, the Ides began a “holy week” of festivals for Cybele and Attis. The Ides was the day of Canna intrat (“The Reed enters”), when Attis was born and discovered as an infant among the reeds of a Phrygian river by either shepherds or the goddess Cybele, who was also known as the Magna Mater (“Great Mother”). 22 March, the day of Arbor intrat (“The Tree enters”) commemorated the death of Attis under a pine tree. Another festival involves A college of priests called dendrophoroi (“tree bearers”) who cut down a tree,suspended from it an image of Attis, and carried it to the temple of the Magna Mater with lamentations. A three-day period of mourning followed, culminating with the rebirth of Attis on 25 March, which corresponds with the date of the vernal equinox on the Julian calendar.
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 no later than the Ides of March. 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 death caused a crisis in the Roman Republic, and triggered the civil war that would result in the rise to sole power of his adopted heir Octavian (later known as Augustus). 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 knights who had fought against him under Lucius Antonius, the brother of Mark Antony to avenge Caesar’s death.