Even the most dispassionate student of Shakespeare probably knows the line, “Beware the ides of March,” from Act I, scene ii of the play Julius Caesar, which was first performed in 1599. The imperative is a soothsayer’s warning to Caesar, “shriller than all the music.” Not only does it land on deaf ears, but Caesar also recounts the prophecy on the day of his own death. On his way to a Senate meeting, in the first scene of Act III, Caesar says to the soothsayer, as if to justify his disbelief, “The ides of March are come,” to which the prophet replies, “Ay, Caesar; but not gone,” to let him know that the danger has not yet passed.

History confirms that because Roman society was superstitious, the real-life dictator Julius Caesar employed a seer named Spurinna, who repeatedly warned him about impending treachery for a month leading up to the ides of March. Spurinna was a haruspex, skilled in the art of analyzing the entrails of sacrificial animals, such that he purportedly could predict the near future. The emperor failed to heed Spurinna’s advice and was stabbed to death by a group of 60 conspirators, led by Marcus Junius Brutus and Gaius Cassius Longinus, on March 15, 44 B.C.

The conspirators’ motive for assassinating Caesar, who had declared himself dictator for life, was the restoration of the Roman Republic. When Cassius and Brutus first begin to conspire against Caesar, in Shakespeare’s account, Brutus professes love for Caesar but decides that he loves Rome more. Alas, Caesar’s assassination prompted civil wars, and the only person to emerge victorious was Caesar’s great nephew, Octavian. Having had no sons, Caesar had adopted Octavian, who ultimately became the first emperor of Rome and ruled for 40 years. In 26 B.C., the Roman Senate gave Octavian the name Augustus, which means “exalted one.”

In the ancient Roman calendar, the ides was simply a name for the midpoint of each month, signifying the rise of a full moon. The first day of the month was called the kalends and the seventh day the nones. Days between the first of the month and the seventh were referred to as “before the nones,” and days between the nones and the ides as “before the ides.” In longer months, like March, the ides landed on the 15^th day of the month, and in shorter months, they were on the 13^th day. Several religious festivals were held on the ides, and that date was also considered to be a deadline for settling debts.

One of Caesar’s sweeping reforms as dictator of Rome and its territories was the establishment of the Julian calendar to replace the ancient Roman calendar, which originally appears to have had only 10 months, beginning with Martius, or March. Though modified slightly in the 16^th century, the Julian calendar is still used today. In 8 B.C., Augustus renamed the month Sextilis after himself — August — just as Julius Caesar had done with the month of July and the Julian calendar itself. The last four months of the year continue to bear names based on their original Roman numerical values: September was the seventh month, October the eighth, November the ninth, and December the tenth.

Shakespeare’s Julius Caesar chooses to ignore many portents of his assassination, including his wife Calpurnia’s nightmare, in which Caesar’s statue spouts blood from a hundred wounds. Yet Caesar maintains that he would be a coward to stay home instead of going to the Senate as planned, and his friend Decius (a traitor, unbeknownst to Caesar) tells the dictator the Senate has decided to give him a crown that day, thus sealing his fate.

With bravado, Caesar remarks in Act II, scene ii, “It seems to me most strange that men should fear, seeing that death, a necessary end, will come when it will come.”