I have taken some liberties with small historical details, compressing events, places, and timelines in order to serve the story. The Dacian Wars and the Cyprus rebellion have been moved up a bit in time to suit Vix’s convenience, and Hadrian’s year in Athens as magistrate moved back. Annia Galeria Faustina was in reality Sabina’s half-niece instead of her half-sister (their family tree is a Rubik’s cube of connections and counterconnections that desperately needed simplification) and although the date of Faustina’s betrothal to Titus is not known, it probably happened a few years earlier than I made it happen here, as did Sabina’s own marriage. It’s not known whether Titus ever served as tribune in a legion, though it was a traditional starting point for many young politicians, and he was notoriously averse to the military for the rest of his life. To suit Titus’s career I have also fudged a few building dates on projects such as Trajan’s Column and his massive public baths, which both still stand today as splendid ruins in the middle of Rome. Vix’s legion, the Tenth Fidelis, is fictional, but its exploits are based on those of real legions that took part in the Dacian and Parthian wars. Hadrian was present at the siege of Sarmizegetusa, though as the legate of a different legion, and the Dacian and Parthian wars unfolded much as I have described them.

Conversely, many of the book’s more outlandish details are entirely true. The idea of secret astrological prophecies sounds ridiculous, but historians record that Hadrian recieved such a prophecy at a young age foretelling his rise to the purple (of course, many other emperors supposedly did too). Trajan’s various near-death experiences are also fact—he narrowly missed dying at Hatra when an enemy archer spotted him without his helmet, and he also escaped being crushed to death by the devastating earthquake in Antioch. Mention is made, during that earthquake, of a woman trapped in the rubble who managed to keep both herself and her newborn baby alive on her own breast milk until they could be rescued.

A modern audience might find it surprising that two of Rome’s most famous and effective emperors were openly homosexual, or at least bisexual with a strong preference for men. Ancient Romans held a very relaxed view of sexual preferences: Bisexuality was the norm rather than the exception among upper-class Roman men. Both Trajan and Hadrian made political marriages, but their relationships with their wives are assumed to have remained platonic since both men openly preferred male lovers. Neither emperor was ever reviled as less of a man or a soldier.