I should point out that there was no bishop of Saint Albans in the twelfth century, although there is now, so mine is a fictional predecessor. However, the dispute between the abbey of Glastonbury and the bishopric of Wells is a historical fact; the two were at daggers drawn for centuries.

Also, in those days, the title of doctor was reserved for masters of philosophy, et cetera, and not for medical men, but, again, I’ve used the anachronism in the interest of clarity.

The use of trial by battle to prove a property dispute had an extraordinarily long life, though it began to die out when Henry II’s judicial reforms were introduced. The last known instance of it is thought to have taken place during the monarchy of Elizabeth I. It wasn’t abolished from the statute books until the eighteenth century in the reign of George III.

As to the introduction into my story of Brother Peter, there is some dispute over whether the Benedictine monks-which is what the brethren of Glastonbury were-used lay brothers to relieve them of laboring work, but I am assured that in some cases they did.

In modern times there has been speculation that leprosy, so rife in the Middle Ages, was not leprosy at all, but that other disfiguring diseases were mistaken for it. This is now mainly being disproved by the new ability to test the bones found in the graveyards of ancient lazar houses, where it has been discovered in some cases that seventy percent of the dead suffered from the leprous condition proper.

In the matter of the writ Morte d’Ancestor, the twelve men hearing the case were technically not jurors as we would understand them now; they were an “assize,” men cognizant of the facts concerned. But again, for simplification, I have called them a jury.

I am occasionally criticized for letting my characters use modern language, but in twelfth-century England the common people spoke a form of English even less comprehensible than Chaucer’s in the fourteenth; the nobility spoke Norman French, and the clergy spoke Latin. Since people then sounded contemporary to one another, and since I hate the use of what I call “gadzooks” in historical novels to denote a past age, I insist on making those people sound modern to the reader.

I OWE KNOWLEDGE of such Welsh words as I’ve used to Mr. Alan Jones of Datchworth, who was so kind as to instruct me in what he calls “the language of Paradise.” Thank you, Alan.

As ever, I’m grateful to the wonderfully efficient team at Putnam and especially my editor, Rachel Kahan. I just wish sometimes that she and my equally marvelous agent, Helen Heller, didn’t persist with their advice being right in every single instance.

The London Library, that great reservoir of knowledge, stops me from making more historical mistakes than I do.

And I don’t know what I’d accomplish without the help that my daughter, Emma, gives me in coping with secretarial and financial matters, or without Barry, my husband, abandoning his own work to accompany me on research trips.

ARIANA FRANKLIN, a former journalist, is a biographer and author of the novels City of Shadows, Mistress of the Art of Death, and The Serpent’s Tale. She is married with two daughters and lives in England.