The other day a reader asked me, “How much of your historical novels are true? How much did you make up?”

It’s a complicated question, and it deserves a complicated answer!

There is not one word of my historical fantasy novels that I know to be false.

That said, very often there are things we cannot know. We cannot know if anyone “really loved” anyone else, or what people’s personal spiritual experiences or beliefs were, or how they felt about their children or their families. We don’t know these things about the people in our lives that we know well! We may make informed guesses based on their behavior and their words, but we don’t truly know. We may say, “If he loved her he wouldn’t cheat on her all the time,” or “She spends a lot of time at church and she talks about it a lot, so obviously religion is very important to her,” but we don’t truly know. We just guess.

It’s a lot harder to guess over the gulf of two thousand years, when we’re guessing based on fragmentary original sources. Often, we’re missing key pieces of the puzzle. For example, no one knows where Cleopatra spent the formative years of her adolescence when her father the king was deposed and went into exile. At the time, she had four brothers and two older sisters ahead of her in the succession, and where she was and what she was doing was so unimportant that it was not recorded in any source that survives to us. Perhaps the most important years of her life, when she changed from child to woman, are entirely missing.

In my novel, Hand of Isis, I’ve made my best guess based on the sources and on logic. For example, if she had accompanied her father to Rome, it is likely she would have been mentioned, since we have many sources and records of his visit there. Had he brought his teenage daughter, surely someone would have commented on that fact. In later years she showed herself to be very sympathetic and knowledgable about Egyptian temple life, and donated vast sums of money to various temples. She demonstrated the kind of knowledge that suggested she had lived in Egypt outside of Alexandria, something unheard of for a Ptolemaic princess. It seems likely to me that she spent those years of exile in sanctuary in one of the temples, as young girls of good family often did when war or illness had made them orphans. I chose the Temple of Bastet at Bubastis because it was one of her favorites in later years, and because Ptolemaic queens had patronized it for several generations. It had been a favorite of Queen Arsinoe, for example, who may have stayed there for some time in her old age and widowhood.

But we cannot know. Unless some new cache of documents comes to light, the best guess is all we can do.

On other subjects there is too much material rather than too little. How many slaves were there in Rome in 44 BC? Many different scholars have many different answers, depending on how they parse the original documents. It is a matter of intense scholarly debate and controversy. In a situation like that, I read the competing arguments and some of the documentation they’re based upon, and came to a conclusion of my own, much as I would if I were writing a dissertation on the subject. And, like a dissertation, not every scholar in the field will agree with my conclusions. I have, of necessity, favored some positions above others because I felt that they were more likely and logical.

In short, it is as true as I can make it. But Hand of Isis is a work of fiction, not biography. I have extrapolated and anticipated, put things together in ways that seemed emotionally true but for which there is not and can never be documentary evidence. Did Cleopatra really love Antony? Did she love Caesar? Love leaves no tracks on the historical record — just on our hearts.