In the complex world of the Roman calendar, each month had a day called its ides. In March, May, July, and October, the ides fell on the 15th of the month. In the remaining months, the ides fell on the 13th. Ides comes from the word iduare, which means, “to divide” and literally signified the division of a month into two equal parts. The Roman calendar divided each month into kalends, nones, and ides, each celebrated in their own ways, indicating lunar events, and serving as a calendar for the common citizens. The ides was a day traditionally marked for ritual offerings and sacrifices.
Religious and political leaders kept calendars private and were often adjusting the length and structure to remain in sync with the lunar and seasonal changes. In the Roman and Julian calendars, the term ides was commonly used, equivalent to using such modern terms as next week, today, tomorrow, or yesterday.
The ides of March took on a whole new meaning in the year 44 BCE. It was on this day that Julius Caesar, emperor of Rome, was assassinated by a group of nobles in the Roman Senate. William Shakespeare captured this historic assassination in his play Julius Caesar. In Act One, Scene Two, a soothsayer proclaims a warning to Caesar in the infamous line, “Beware the ides of March.”
After the Julian calendar, inspired by Julius Caesar, displaced the Roman calendar in 46 BCE, the term ides was used only colloquially to denote the middle of the month. Those living under the traditional Roman calendar most accurately interpreted the ides as the 15th of the month. With the passing of time, the expression “beware the ides of March” came to signify the prediction of doom, much like the aura of superstition that associates bad luck with Friday the 13th.
See also Caesar, Gaius Julius; Calendar, Gregorian;
Calendar, Julian; Calendar, Roman; Rome, Ancient
Evans, G. B. (1974). The Riverside Shakespeare. Boston: Houghton Mifflin.
Feeney, D. C. (2007). Caesar’s calendar: Ancient time and the beginnings of history. Berkeley: University of California Press.
Michels, A. K. (1967). The calendar of the Roman Republic. Princeton, NJ: Princeton University Press.