Readers of the Legions of Honour series sometimes assume the hardest part of writing Roman Britain is the battles. It isn't. Battles are, if anything, the easy part — chaos reads as chaos. The hard part is everything around the battle: how a Roman patrol actually moved through unfamiliar territory, what a supply line looked like four hundred miles from Rome, how quickly rumour could outrun a legion on the march.
For Measured Ground, book four, the research question that shaped the whole plot was disarmingly administrative: how did Rome actually survey conquered land? The answer — meticulously, and with a bureaucracy that has more in common with a modern land registry than most people expect — became the engine of the book. An empire that measures everything eventually measures its enemies too. That's not a metaphor I imposed on the history; it's just what the history does if you sit with it long enough.
I try to hold two things in tension in this series: real Roman military and administrative practice on one side, and character choices that feel true to people, not to textbooks, on the other. Gaius doesn't behave like a Roman commander because I've decided he should represent "Roman values." He behaves like a man who's spent years choosing, again and again, what he can live with.
The unglamorous truth is that most of my research never appears on the page directly. It shows up as confidence — the sense, I hope, that the world keeps existing in scenes the camera doesn't linger on. That's the whole job, really: build enough of the iceberg that readers trust the tip.