Sabine Baring-Gould’s Book of Were-Wolves devotes chapters eleven through thirteen to a single case study: that of Gilles de Laval, Maréchal de Retz — more commonly known today as Gilles de Rais. “The history of the man whose name heads this chapter I purpose giving in detail,” writes our author, “as the circumstances I shall narrate have, I believe, never before been given with accuracy to the English public.” Crediting Paul Lacroix as his main source, Baring-Gould then warns the reader that his summary of the case will cover “horrors probably unsurpassed in the whole volume of the world’s history.”
I don’t really need to summarise these three chapters, as the life of Gilles de Rais has been covered extensively elsewhere (with more up-to-date research than was available in the 1860s, as well). Suffice to say that Baring-Gould’s distinctive blend of the matter-of-fact and the macabre is on full show: “Henriet counted thirty-six children’s heads, but there were more bodies than heads. This night’s work, he said, had produced a profound impression on his imagination, and he was constantly haunted with a vision of these heads rolling as in a game of skittles, and clashing with a mournful wail.”
And if you’re wondering whether Baring-Gould is making the case that Gilles de Rais was a werewolf, the short answer is no. By this point, he seems to be filing any acts of extreme sadism in the category of lycanthropy.