MDxxxviii?

When should writers of historical fiction disregard historical accuracy in favour of clarity for the reader? Or. to put it anther way, how hard should writers expect their readers to work in order to follow the narrative?

General advice is that writers should not underestimate their readers; that readers like to work things out for themselves and do not need to have everything explained in detail. On the other hand, some readers can't, or don't want to, do that. I don't want readers to think I have been inaccurate, or to be put off reading, because I have made things over complicated in the pursuit of strict historical accuracy.

In Inheritance of Secrets my heroine visits Tonbridge, a market town dating from the Middle Ages if not earlier, and Tunbridge Wells, a spa town four miles from Tonbridge which developed from the middle of the seventeenth century.

Those spellings only became fixed in the late nineteenth century. At the time the book is set, Tunbridge was the more common spelling for both places. The Kent historian Edward Hasted, who was writing at that time, used Tunbridge for both.

So should I have used Tunbridge to refer to the market town for the sake of historical accuracy? But readers who didn't know of the variation in spellings might think I had been inaccurate! In the end I decided on the modern spelling, in order not to distract readers from the narrative.

In the work I'm currently preparing for publication, my contemporary characters are reading some historical documents. At the time these documents were (supposedly) written, the year would have been expressed in Roman numerals. Will readers who aren't familiar with Roman numerals be put off by this, and by the spelling and punctuation (or lack of it) likely to be found in documents of that period?

I want to include the actual text of the documents, for a  variety of reasons. The characters will reiterate the main points of information in the discussions they have after they have read them. I hope readers who have no trouble following the archaic style of the documents don't consider this to be repetition and dumbing down.

Writers of purely contemporary fiction don't have this particular problem, but any novelist who uses specialist knowledge as part of the background or setting for the story must address the question of how much to explain. There will always be readers who think the writer has gone too far in one direction or the other. The most important thing is to be sure that readers can follow the development of the plot.