Desertion was always a problem for a professional army with a harsh discipline and enlistment for twenty-five years. Fear of punishment appears to have been a common motive for flight, but we should also note that one first-century AD commander was seen as especially severe for executing men recaptured after deserting for the first time. As always, I have tried to represent the Roman army and how it worked as accurately as possible, but must once again emphasise that there is so much that scholars do not know, since many aspects of day-to-day practice have not been preserved in our sources. Novels like this allow me to try out ideas based on lifelong study of the army and the empire, but must remain guesses.

Legio VIIII Hispana is famous as the legion that supposedly disappeared in what later became Scotland, inspiring among other things Rosemary Sutcliffe’s famous children’s adventure, The Eagle of the Ninth. (The BBC TV dramatisation of the story was one of the things that first inspired my fascination with all things Roman.) While the legion did cease to exist sometime in the first half of the second century AD, we do not know what happened, or whether it was destroyed and never reformed or disbanded for other reasons. The odds are against the legion being destroyed in Britain, but evidence for its activities are so limited that we do not really know where it was or what it was doing at the time of our story. I made it the legion in our story because its name is well known, it has a connection with Britannia like many of our characters, and I wondered whether some readers would see the name and anticipate that this would be the story of its demise. For those interested in the evidence for the fate of the VIIII Hispana and a good deal more about how we understand the Roman army and the evidence for it, I recommend Duncan Campbell, The Fate of the Ninth: the curious disappearance of one of Rome’s legions (2018).

In The Fort, Ferox and the rest of them were stuck inside a Roman army base defending it against a far more numerous enemy. In The City, I wanted to look at the other side of things and show the Roman army besieging a well-defended stronghold – in this a case a community caught up in machinations on either side through no fault of its own. In the late Republic and under the Principate, the Romans developed a highly sophisticated and very effective system for taking strongholds. Even so, this remained one of the most difficult operations in ancient warfare, and sometimes the legions failed, as they did at Hatra. While fictional, I have done my best to show how the Romans and defenders went about these things, the cat-and-mouse game as each tried to outwit the other, and the slow pace with sudden dramatic shifts in the balance between the two sides.