HarperCollins has pre-empted UK and Commonwealth rights, excluding Canada, to a historical debut set in Saxon times.
Editor Kiera Godfrey and publishing director Louisa Joyner bought the rights to The Shadow on the Crown by Patricia Bracewell from Hal Fessenden at Viking US.
Set in 1002AD, it follows a 15-year-old girl betrothed to the Anglo-Saxon king, who falls in love with his son.
Godfrey said: "I have been looking for the next big debut in the women's historical area and Patricia Bracewell is most certainly it. I am completely gripped by Patricia's fantastic characters, strong women and complicated men, great romantic drama and intense family relationships, set in dark and brooding Saxon times."
A publication date is to be confirmed.