Let's be clear; Mithridates was a monster. He cold-bloodedly ordered the killing of 80,000 (mostly) innocent civilians in a single day, and was quite happy to use torture or execute hostages if it suited his purposes.

He was also brave, charismatic, resolute and prepared to lead from the front. I loved writing this book. There were titanic battles, epic sieges, world-class political skulduggery and pirates, unfaithful wives and sundry plots and poisonings as well. It would make an epic TV series.

Yet, for some reason, no-one has presented a book on Mithridates to the general public for almost a century, and his feats have been largely forgotten. Therefore I had to do my work from scratch, poring over ancient maps, wrapping a wet towel around my head as I struggled with obscure Greek texts, and occasionally building a battlefield out of books and jackets on the lounge floor and moving model infantrymen around as I tried to work out how it all might have happened.

The challenge was to put in enough detail to make this a comprehensive history, yet still keep it entertaining enough to be enjoyed by people who have never heard of (for example) Bithynia, and failed to keep abreast of its diplomatic and military position in Cappadocia.

I did this by keeping the focus on Mithridates, and failing this, his soldiers who fought loyally and gallantly in a lost cause. It says a lot about Mithridates that, knowing what the man was capable of, and knowing how the story ends, if I'd been in Pontus when his recruiting sergeants came round, I'd still be tempted to sign up.