Do 200 years make a difference?

I was researching some detail for Gisborne yesterday and on a wonderful site,  Writing the Medieval World, they had used an image for one post from Très Riches Heures by the Limbourg Brothers for the Duc de Berry.

Despite being a generalised commentary, Wikipedia does have rather a good entry on the images.

I saw my first example of Très Riches Heures hanging in a friend’s house about thirty years ago. They had bought the copy in Paris and I remember it hung at the junction of a stair well. I was always mesmerised by the richness of colour and the detail and would stop and stare whenever I walked past. It’s hard to believe that the pigment in the originals in the Musée Condé has stayed so pure since the fifteenth century.

Almost everyone who has read this blog has read parts of the rough draft of Gisborne and they know that it takes place on the cusp of the twelfth and thirteenth centuries. The cover for the book will be in the hands of the designer, of course. But chance Facebook comment when I put a Limbourg image up had me lusting after one of the many images of this glorious Book of Hours for a cover.

My dilemma is the age-old one that rears its head with daunting frequency in historical fiction. How much accuracy?

Because there is a 200 year discrepancy between Gisborne’s part in the Middle Ages and the time of Très Riches Heures. And I just know that some reviewer somewhere would point that out, as if I didn’t know.

Of course all this may not necessarily matter as the designer may have her own ideas of what should go there, but in the meantime, what do you think? Would such a discrepancy in time matter?