The writing guidelines for ALL the London edited M&B series have been tweaked. You can see them here. They are basically the same as before but perhaps with a slightly different emphasis.
The historical one reads like this:
Length: 70,000–75,000 words
Senior Editor: Linda Fildew
Assistant Editor: Sally Williamson
Editorial Assistant: Mimi Berchie
Office: London, U.K.
Do you dream of waltzing in the strong arms of a Regency rake, or maybe of walking on the wild side with a medieval warrior? Our readers’ dreams are wide-ranging, which is why we encourage submissions for all time periods, from ancient civilizations up to and including the Second World War.
Write what you know. Research is key to writing a strong historical romance. While you don’t need to be a professional historian, you do need to be able to bring a period vividly to life through accurate historical detail. The trick? Having done your research, know what to leave in and what to prune out.
There is no limit to the level of sensuality if it seems appropriate to both the characters and the story. We look for a range, from traditional nonexplicit stories through to highly sensual. Any lovemaking should evolve naturally out of the developing relationship.
Story focus. The central relationship is the key driving force of the story. The characters must be convincing because, despite their living in a time distant from our own, the emotions they experience will be the same then as now—love is timeless.
NB: You submit either via the post or email. They want the first three chapters plus a short (1-2 page) synopsis. You can also find more information via the historical podcast.
Lately for me it has been making sure that the central relationship is the driving force. It is where I had to do most of my revisions with Compromising Miss Milton.
Hopefully this helps someone.