Shadow on the Crown covers a few years around 1006, during the reign of AEthelred the Unready in England. Emma, a Norman, is sent to marry AEthelred in order to secure peace between the Normans and the English. But AEthelred is cruel, more interested in another woman, and all but ignores Emma. And Emma finds herself falling for AEthelred's son, Athelstan. Emma struggles to keep her place as queen of England, despite rivals, a miscarriage, and her own dislike of AEthelred. And, of course, she gives birth to Edward, later king of England and called the Confessor. 
 While I love that someone is dealing with this period in history, a generally overlooked one when it comes to fiction, this isn't the very best treatment of it. There just didn't seem to be enough happening to fill up 400+ pages, though 300 or so might have been fine. I think I was also hampered by being a scholar of this era; I knew exactly what was going to happen, and it took some of the charm out of the story. 
 I think this sort of thing is a major reason that I prefer historical fantasy to plain historical fiction; the fantasy adds something new and unique rather than just retelling the stories. If someone doesn't know a lot about English history and is interested in beginning to learn, this might be a good place to start, but for someone who is already familiar with the era, it wasn't as interesting as it could have been.