I was twenty-six years old and had been a soldier of Rome for eight years, six of them in Gaul under Gaius Julius Caesar, when I stood on the north bank of a small river in January and watched my general stand very still for a very long time.
The Rubicon is not an impressive river. This surprises people when I tell them. They expect a broad torrent, something worthy of its reputation, something with the quality of a threshold that announces itself. The Rubicon in January is perhaps twenty feet wide, brown with winter water, moving at a pace that suggests urgency without drama. It is not the kind of river a man would stop to contemplate unless the contemplation was not about the river.
Caesar stood at the bank for — I do not know how long. Long enough that the men around me began to exchange glances. Long enough that even the horses seemed to notice the stillness.
What We Were
Let me tell you what Legio XIII was in January of that year. We were 500 men — one cohort, the advance guard, the rest of the legion two days behind us. We had been in Gaul for six years. We had fought the Helvetii and the Belgae and the Germans and the Nervii and the desperate, extraordinary rebellion of Vercingetorix, which we had broken the previous summer at Alesia after a siege that still seems, in retrospect, impossible. We had built a wall around a hill fort while building another wall to keep the Gallic relief army out. We had held both walls. We had won.
We were, by the January of 49 BC, very tired men who had been very far from Rome for a very long time, and most of what we wanted was to go home. The situation that stood between us and home was a legal one: Caesar's command in Gaul was ending. His enemies in the Senate had made clear that if he returned to Rome as a private citizen, he would face prosecution. He had asked to stand for the consulship in absentia — to let the voters choose him without his needing to surrender command and face his accusers. The Senate had refused.
This was the situation at the Rubicon. Not a military problem. A legal and political problem. The river was not a military obstacle. It was a law.
The Moment
Caesar turned to his officers and spoke. I did not hear all of it — I was further back, with the rear of the cohort — but I heard enough, and I have spoken with men who were closer. He said something about what it would mean to cross. He used the word "iacta" — the die. He may have quoted the Greek playwright Menander: "Let the die be cast." The ancient writers argue about exactly what he said, and I cannot settle the argument from where I stood.
What I can tell you is what I saw: a man of fifty-one years, a general of ten years' experience, a man who had seen more of the world than almost anyone alive, standing at a river's edge in the dark with a decision in front of him that had no good side.
If he crossed: civil war. The deaths of Romans at the hands of other Romans, the worst thing a Roman could do. His own reputation, possibly, destroyed. His enemies in Rome might be right that he was a tyrant, a man who put his own advancement above the Republic.
If he did not cross: prosecution. The loss of everything he had built in a decade of campaigning. The political destruction of him and everyone connected to him.
He crossed.
Ariminum
We reached Ariminum — modern Rimini — before dawn. The town's garrison was small; it offered no resistance and we occupied it without bloodshed. Caesar walked through the streets in the early morning and spoke to the inhabitants and reassured them that no harm would come to them. He was, from the beginning of that campaign to its end, careful about this: the civilian population was to be protected, the towns treated with respect. He understood that he needed Italy more than he needed to conquer it.
Pompey fled Rome with the Senate. He left so quickly that he abandoned the treasury. Caesar marched into a capital that offered almost no resistance, town by town, the great machinery of his reputation doing work that the legions did not need to do. Town after town declared for him. Pompey sailed for Greece.
The war lasted four years. I will not give you all of it. I was at Pharsalus, which was its decisive battle, and I was in Egypt when the news of Pompey's murder came, and I was with the army when it finally ended in Spain at Munda in 45 BC, and by that time there was almost no one left who could remember clearly what it had been like before.
What We Chose
Men sometimes ask me whether I knew, at the river, what we were choosing. Whether we understood that we were not simply crossing a boundary but ending a kind of world.
I did not. I was twenty-six, I was tired, I was a soldier, and my general gave an order. The Republic, which I had sworn to defend, had become a thing that would destroy my general rather than accept his terms, and in such a situation the Republic looked different to me than it looked to the men on the other side. I crossed the river because Caesar crossed it, and he crossed it because there was no other way.
Whether it was the right thing — that question belongs to philosophers and historians. At the bank of the Rubicon in January, it was a cold night, and Caesar stood still for a long time, and then he moved.
Narrator's note: Lucius Petronius is fictional. The crossing of the Rubicon is documented in Suetonius's Life of Caesar, Plutarch's Caesar, and Appian's Civil Wars. The exact wording of Caesar's famous phrase is disputed; Suetonius gives "iacta alea est" (the die is cast), Plutarch uses the Greek original attributed to Menander.