Then of course as an author of historical novels, you have to be just as picky with your surnames because the male characters are mostly known by their surnames.
Oh, when I sent a manuscript to the Romance Novelists Association in the UK a few years ago, it came back saying, "they wouldn't be called by their surname," so wrong, this person had obviously never read any historical letters and documents, men were often only known by their surnames and titles. Case in point in my recent historical blog I've been writing about the romantic relationship between the Poet Shelley and Mary Godwin (who wrote Frankenstein) and later married Shelley, within this I include links to copies of her letters to him and she only ever called him Shelley, never his first name, which was Percy. I have to say in this respect my own novels are not authentic, I'd rather the heroine use the hero's given name. I try and walk this tightrope within my novels of making it an enjoyable read in a modern style of language so the story doesn't get slowed down by working out the meaning of something, while also trying to keep the image of the period of history, so you as the reader feel like you are in it. I think the reader might be questioning why if I only ever had the heroine calling the hero by his surname.