“Beware the Ides of March,” a soothsayer warned Julius Caesar in Shakespeare’s portrayal of the dictator’s murder. According to ancient biographer Plutarch:
A certain seer warned Caesar to be on his guard against a great peril on the day of the month of March which the Romans call the Ides; and when the day had come and Caesar was on his way to the senate-house, he greeted the seer with a jest and said: “Well, the Ides of March are come,” and the seer said to him softly: “Ay, they are come, but they are not gone.”
In the Roman calendar, Idus referred to a specific day mid-month: the 15th of March, May, July, or October, and otherwise the 13th. For reasons unknown, perhaps even to the Romans, Idus was always plural. Shakespeare made Ides plural in English, too. It’s the same word if treated as singular; no related “ide” exists. In practice the grammar is messy. What rule explains why “The Ides are looming” sounds fine, but “The Ides of March were Saint Nicholas’s birthday” would work better with the singular was?
The fated date turned out badly for the dictator who overthrew the Roman Republic. The Ides of March brought other misfortunes over the centuries, including WHO’s global health alert for SARS in 2003. This morning, after months of troubles, March 15 has arrived with no new disaster I’m aware of. So far.
I'm a historian who writes novels and literary nonfiction. My home base is Madison, Wisconsin.