Behind the Book: A Treachery of Legions

I read the Centurion books, Damian Hunter’s series about a Roman soldier, when I was in my twenties. I found them in a secondhand shop and went through all of them over a long weekend. What stayed with me was not the battles, which were good, but the texture around the battles: the cold of a frontier morning, the weight of equipment worn so long the body stops noticing it, the way men who have spent years in close quarters manage each other without any of the machinery civilian life gives you for it. I was already interested in Rome. Those books made me want the intimate version of it, the life inside the legion instead of the map of the campaign.

I was sixty-three when I started writing this one. I had been carrying that weekend around for forty years.

Where did the book come from?

It came out of a lifetime of Roman inputs, not a single source. The Centurion books focused the appetite, but the forty years in between filled it. I watched the old BBC I, Claudius, adapted from Robert Graves, probably a dozen times, and I still think it is one of the best things ever made about Rome, even with British actors and English accents standing in for Romans. I loved HBO’s Rome, and I am still sorry it lost its funding, because it was built for five seasons and would have been a wonderful thing at full length instead of the shortened run we got. I had an architecture book that walked through the building of all the ancient civilizations, the Roman aqueducts and the rest, and I traced them through and learned how the physical empire was put together.

Then there was the period itself. The Year of the Four Emperors, 69 AD, when four men held the throne in twelve months, is one of the most revealing moments in Roman history, because the machinery that holds an empire together is briefly visible while it is breaking down. And Vespasian, the man who came out of that year on top, was the general who commanded during the Judean revolt, which pulled in another whole body of material I had already absorbed: I read Josephus, and the film Masada was in there too. All of it pooled together until the Year of the Four Emperors gave me the one place to put a man who had spent his life learning how things work.

Why Marcus Antonius Primus?

Because he is a major figure who is not well understood, and the gap is the whole opportunity.

Primus is the man who, more than anyone, won the civil war for Vespasian. He commanded the Danubian legions, and he moved them and marched on Rome and delivered the victory. Without him, Vespasian probably does not take the throne, and I suspect Vespasian knew it. And this is what drew me: for doing the decisive thing, Primus got no triumph. He simply retired and disappeared from history. His early life is undocumented. His later life is undocumented. The man who made the emperor was quietly set aside once he had served his purpose, and the record goes silent around him at both ends.

That silence is exactly what a novelist wants. A real man at the hinge of the whole war, essential to the outcome, and then almost nothing on either side of the public career. I wanted to show a fictionalized version of what he may really have been like, to fill in the person the record left blank. And he turned into the perfect vehicle for the thing the book is really about. The official story of 69 AD is a story about emperors. The actual mechanism, the thing that decided it, was a competent frontier general moving legions without orders and then being discarded, because a man who can do that is dangerous to keep close once the throne is secure. Primus getting no reward is itself a lesson in how power works, which is the book’s whole preoccupation.

What was the choice at the center of it?

Primus had a real decision to make. He could have backed Vitellius, who held the throne, or Vespasian, who was coming for it. He chose Vespasian, for reasons the book works through, and that choice was the hinge of history. If he goes the other way, there is no Vespasian as emperor. A frontier general’s decision about which claimant to support decided who ruled Rome.

That is the kind of moment I wanted at the core of the book, because it is where the how-things-work theme becomes a single human decision. Not a battle, not a speech, a man on a frontier weighing which way to move and understanding that the empire will turn on it. The battles are in the book, First and Second Bedriacum, the sack of Cremona, the burning of the Capitoline temple, all documented, all rendered. But the spine is the choice, and the man making it.

Why invent the private life?

Because a documented public career is not a character, and I needed a character. Primus is the protagonist, the man the whole book lives inside, and a career is not a person. So I built the private life the novel needed. Julia, the wife, is a more political marriage. Brunhild, the woman across the river, is the love interest, because a novel wants one. The Danubian posting as I describe it, and the sword scene the book opens on, are invented too. The historical record gave me the war and the political figures and the movements of the legions. The interior man I made.

I want to be plain that the romance is not the focus. Julia and Brunhild are there to make Primus a person and to give the book some warmth, not to carry it. This is not a book about a marriage or a woman across a river. It is a book about the man, the career, the choice, and the machinery of how Rome worked when the official version broke down. The private life is the equipment that turns a name in Tacitus into someone you can follow for four hundred pages.

That is also just how I write. This is a character-driven book, more than a plot-driven one, which is my preference. I would rather follow a man closely through a life than run a plot at speed, and Primus, with his blank early years and his quiet disappearance, gave me a life worth following.

What made it hard to write?

The research. This took more of it than anything else I have written, and the reason is specific. This is not the Rome of I, Claudius. That is the Julio-Claudian era, Augustus through Nero, and it is the Rome most people carry in their heads. This book comes after. By 69 AD the empire had changed. The Republic was long dead, whatever nostalgia still clung to its forms, and the imperial system was fully in force. The relationship between the legions and the throne, the role of the Senate, the way a provincial general could become a claimant, all of it was different from the world I already knew from the earlier period.

So I could not lean on what I knew about Claudius and his family and simply move it forward twenty years. I had to learn the later period on its own terms: the Flavian moment, the conditions that let four emperors rise and fall in a year, the specific political and military machinery of that exact window. Tacitus’s Histories, incomplete and biased and essential, was the spine of it. Where the record was clear I tried to honor it. Where it was silent I invented what seemed true. That line, between honoring the documented and inventing the plausible, is the whole discipline of this kind of book, and getting it right is most of the work.

How does it fit with the rest of your work?

It is another character-driven book, which is where I am most at home, and another exercise in living inside a mind that is not my own, this time a first-century Roman general reconstructed from a few lines in the record. Across these Behind the Book essays that has been the through-line: a cat, a galaxy, an artificial mind, prehistoric people, a reaper. Primus is a quieter version of the same instinct, a real man history barely described, rebuilt from the inside until he reads as a person who could have done the documented things for reasons that feel true.

And it is the one that asked the most of me before I could write a word, because you cannot reconstruct a man from a period you only half understand. I had to earn the Rome of 69 AD first, and then put Primus in it, and then find out who he was by writing him.

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