March 15th in Roman History
By: TammyJo Eckhart, PhD on 3/11/2019


This week, I want to draw your attention to an important date in Roman history: March 15, the Ides of March, the date on which Julius Caesar was assassinated in 44 bce. While the murder of a would-be king in late Republican Rome would be noteworthy for historians, March 15 was more than that, so today I want to dig a bit deeper into the assassination and the date itself to try to figure out the benefits and challenges the murderers faced on that particular date.

Let’s begin with the death of Julius Caesar, since I imagine most of you found this article either by trying to find out more about his murder or about the man himself. To be simple, this date was the one on which the dictator – a Roman political office undoubtedly misused by Caesar as it had been by others before him – was killed by a group of senators. The reasons for the assassination were numerous and are still discussed by historians today. Whether motivated by fear or hope, the Senate and people of Rome had granted Caesar more and more powers and authority. At some point as many as 60 senators, or 10% of the Senate, decided they’d had enough. They planned and carried out his execution. Why did they decide to strike Caesar down on March 15?

Greek and Roman writers such as Plutarch and Suetonius claimed after the fact that soothsayers accosted Caesar before March 15 and warned him. Of course, much later authors like William Shakespeare and Thornton Wilder popularized this idea. Did such a warning really happen, or was it a way for later writers to comment on Caesar’s personality or the civil war that followed his assassination?

Evidence from the 40s and 30s bce is tainted with political bias to begin with, yet no sources that I am aware of specifically discuss the date. The soothsayer story serves several narrative functions that could have been used to advance either side in the civil war. Ignoring a warning makes Caesar look arrogant, a trait his critics could have used. If he hadn’t ignored it, maybe he, and by extension the Roman world, was fated to fall and then rise again, a situation that would have been helpful to any later man who took up the title Caesar after him. Fate or not, the Ides of March, March 15, was important for reasons other than the assassination of Julius Caesar. The importance of March 15 might provide clues as to why it was selected.

I think we can quickly dismiss any financial connection, even though many of us might have been taught that the date was some sort of debt or tax collection day. The evidence for that is minor and seems to conflict with other details about the date’s importance by 44 bce. Likewise, the original meaning of the Ides as the date of the full moon seems to have fallen by the wayside well before the assassination, so it seems ridiculous to consider anything lunar as a cause.

For a relatively short period in Roman history, 222-153 bce, newly-elected Consuls were installed in office on March 15. While it might be tempting to see some message about the role of the Consul and Senate in the conspirators’ actions, after that 70-year period, the Consuls were seated on January 1. If Brutus and the others wanted to send a message about consular power, the authority of the Senate, and Caesar, wouldn’t January 1 or the day before have been a better choice?

The traditional Roman New Year was celebrated on March 15 with religious and secular activities on the banks of the Tiber River. Sacrifices, music, food, and wine all honored the goddess Anna Perenna and asked her to grant everyone and Rome a good year. In the first century ce, Ovid claimed her festival was more love fest than sacred rites, but regardless of its exact nature, modern scholars see it as public and private worship that would have drawn the majority if not all of the city. Could the conspirators have thought they’d have fewer eyes upon them if they chose a day when average citizens were off celebrating?

Furthermore, every month’s “ides” was a day sacred day to Jupiter, and as his priest (or flamen dialis, in Latin), a position Caesar had held since his youth and still held as Pontifex Maximus, the day should have involved sacred rites for him. Those rites wouldn’t have taken all day, so Caesar would have been free to join in the Festival of Anna Perenna or attend meetings later. Perhaps the conspirators thought their target would not expect them to attack him on a day when two gods were being honored, but that doesn’t really tell us anything – it wasn’t unusual for two or more gods to be honored on the same date in the Roman calendar, so why pick that date in particular?

The conspirators had to have known that murdering Caesar on March 15, a date when two deities were honored, might be seen as sacrilegious, wouldn't they? Add to that the fact of Caesar’s lifetime appointment as Pontifex Maximus, and one could certainly make a case that gods-fearing Romans may have seen the murderers as evil—not to mention the fact that senators had sworn an oath to protect Caesar. After the deed was done, the conspirators marched up to the Capitoline Hill with a makeshift army of gladiators, showing that they were certainly aware that many people would not agree with their actions, not only for political reasons but potentially for religious ones. There were thus good reasons not to select March 15. There must be more information we can use to determine why March 15 was the chosen date.

Julius Caesar’s new calendar system had begun on January 1, 45 bce. While the calendar used by the Western world today is still nearly identical to Caesar’s, it was a radical change for Rome. To be blunt, March 15 in 45 or 44 bce was not the same day of the year as it had been in 46 bce or in the rest of Roman history up to that point. The Roman calendar was full of economic, state, and religious holidays, and yes, those had drifted out of alignment with the seasons, but to suddenly add three extra months—as Caesar had to do when instituting his new calendar—was a big adjustment. Could the conspirators have been sending a message about the new calendar? That seems like a petty reason at best, not that people haven’t been murdered for more minor affronts in history, but it seems unlikely in this case.

One final consideration of the date that some scholars have raised is that Caesar was planning to leave Rome on March 18 to raise an army for his next military campaign. That still left March 16 or 17 free, not to mention the days before the Ides of March. If there were indeed 60 conspirators, only 23 stabbed the dictator. Was the 15th the date when they could get together enough men to perform the deed without risking having just a handful of conspirators present, who might back out? We have no evidence one way or another, but that at least would explain why the conspirators risked angering both men and gods on that date.

We may never know why they chose March 15, but we do know that the date stuck in Octavian’s mind as forever associated with his great uncle and adoptive father, Julius Caesar. Hence, it is no coincidence that in 40 BCE, the Ides of March was the date Octavian chose to stage the executions of hundreds of defeated senatorial and equestrian foes who had fought against his army at Perugia earlier in the year. Not only was it an anniversary, but he also tied the newly-deified Caesar to both Jupiter and Anna Perenna through what ancient sources describe as a religious sacrifice. The would-be saviors of the Republic, having been utterly routed at the Battle of Philippi, instead gave the allies of Caesar more propaganda to work with by picking March 15.

Soon you may be able to visit the sites connected to Caesar’s murder on almost any day, if a plan currently under consideration goes through in Rome.

Recommended reading by a major contributor to Rome Reborn: Barry Strauss, The Death of Caesar: The Story of History’s Most Famous Assassination. 352 pages. Simon & Schuster (2015). Available in hardback, paper, and Kindle from Amazon.

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