Caesar's first wife died in 67 b.c. and he made a politically convenient second marriage, taking as wife Pompeia, the daughter of Pompey, who was then at the height of his career.

In 62 b.c. a certain young scapegrace named Publius Clodius (called "Pulcher" or "good-looking") played a rather foolish practical joke. He dressed himself in women's clothing and got himself into Caesar's house at a time when a religious festival was in process which only women could attend.

He was caught and it was a great scandal. Many whispered that it could not have been done without the co-operation of Pompeia and even wondered if Clodius might not be Pompeia's lover. Pompeia was almost certainly innocent, but Caesar divorced her at once with the famous remark that "Caesar's wife must be above suspicion." Actually, he was probably tired of her and was glad of a face-saving excuse for the divorce.

After Caesar had formed the triumvirate with Pompey and Crassus, he married again, for the third and last tune, to Calpurnia (or Calphurnia, as Shakespeare calls her). She was a daughter of one of Pompey's friends, and it was therefore, in a sense, another political marriage.

—Act I, scene ii, lines 3-4

Antonius, it seems, will be one of those who will race along wielding the goat-hide thongs at the Lupercalian festival. Since Calphurnia has had no children, and Caesar would like a direct heir, it will be useful for her to be struck.

The Antonius referred to is Marcus Antonius, far better known, in English, as Mark Antony. He was born in 83 b.c. and was thirty-eight years old at the time of this Lupercalian festival. He was related to Julius Caesar on his mother's side and had joined the general while he was in Gaul. He had remained loyally pro-Caesar ever since.

Mark Antony had been tribune in 49 b.c. when Pompey and the Senate were trying to force Julius Caesar to come to Italy without his army. Mark Antony and his fellow tribune did what they could to block senatorial action, then fled to Caesar's army, claiming they were in danger of their lives. Since tribunes were inviolate and might not be harmed, Caesar had the excuse he needed to cross the Rubicon with his army.

While Caesar was in Greece and Egypt fighting the civil war, Mark Antony held the fort in Rome itself and didn't do a very good job of it.

Caesar continued to value him for his absolute loyalty, however, and they remained together to the end.

And then a voice calls Caesar's name. It is a soothsayer, a man who foresees the future. This time his message is a simple one:

—Act I, scene ii, line 18

To understand the matter of "the ides" we must consider the Roman calendar, which must set some sort of record for inconvenience.

Each of the Roman months has three key dates and the other days are defined as "so many days before the such-and-such key date." Nor are the key dates regularly spaced or quite the same from month to month.

The first day of each month is the "calends" of that month.

Not long after the calends come the "nones." The nones fall on the fifth day of January, February, April, June, August, September, November, and December, and on the seventh day of March, May, July, and October.

The word "nones" means "nine" because it falls nine days before the third key date, the "ides," where the nine days count the day of the ides itself. The ides, therefore, fall on the fifteenth day of March, May, July, and October, and on the thirteenth day of the other months.

From all this we gather that the "ides of March" is what we could call March 15 today. The Lupercalian festival, which falls on February 15, is not, however, on the "ides of February," for that date would be what we now call February 13.

Calmly, Caesar ignores the mystic warning and passes on to the festival. The incident of the soothsayer is not a Shakespearean invention, but is referred to in Plutarch.

That, of course, does not necessarily make it authentic. The event of the ides of March was so dramatic and so clearly a turning point of history that numerous fables arose afterward of all sorts of supernatural omens and forebodings preceding it. The incident of the soothsayer is only the most restrained and dramatically satisfying one of them.

After Caesar and his party pass on, two men remain behind: Brutus and Cassius. Cassius asks if Brutus intends to watch the festival and Brutus says he won't, for:

—Act I, scene ii, lines 28-29

No, he is not gamesome (that is, "merry" or "gay"). The Romans, somehow, usually aren't in literature. They are generally presented as grave, portentous, dignified men, given to declamations in high-sounding phrases, and that is exactly how Brutus is presented.

He is Marcus Junius Brutus, born in 85 b.c., and therefore just past forty at this time.

Brutus was the "Republican" most idealized by later historians, but he was by no means an admirable character in real life.

To begin with, he was a nephew of Cato, one of Caesar's most obdurate and steadfast enemies. It is not surprising, then, that Brutus was also an enemy of Caesar's to begin with. Indeed, he fought on Pompey's side in Greece and was taken prisoner when Pompey was defeated.

Caesar, however, followed a consistent policy of leniency toward his enemies, feeling, perhaps, that in this way he converted them to friends and healed the wounds inflicted by civil war. So Brutus was pardoned and set free.

The policy seemed to have worked in Brutus' case, for he behaved as though he were converted from a Pompeian into a sincere Caesarian. When Caesar went to Africa to take care of the senatorial armies there, those had, as one of their most important leaders, Cato, who was Brutus' uncle. And yet Brutus remained one of Caesar's lieutenants and served him loyally in the province of Cisalpine Gaul (in what is now northern Italy).

Later on, crucially and fatally, he abandoned Caesar once again. The later idealization of Brutus has him acting out of conviction and principle, but a glance at his career before the opening scenes of Julius Caesar would make it seem that he was, rather, a self-serving turncoat.

Brutus is unwilling that his lack of gamesomeness should interfere with Cassius' pleasures. He says:

—Act I, scene ii, lines 30-31

Cassius' full name is Gaius (or Caius) Cassius Longinus, and he is a capable soldier. He went with Crassus to the East as second-in-command. After the disastrous defeat which almost destroyed the Roman army, thanks in good part to Crassus' incapacity, Cassius took over and brought what was left of the army safely back to Roman territory.