In the 7th century, Edwin has found refuge with Rœdwald, king of the East Angles. Edwin is the king of Deira and Bernicia, but he was long ago exiled when Aethelfrith usurped his throne. Edwin learns that Rœdwald is plotting to turn him over to Aethelfrith, and that provokes him to take back his kingdom.
Over time, through wars and alliances, Edwin is able to overcome his enemies and become High King of Britain. One of these alliances is his marriage with Aethelburh, daughter of the king of Kent, who is Christian.
I didn’t get terribly involved in the novel. I’m not sure if my problem was the flat characterization, the emphasis on battles and religion, or the lack of any sense of the characters’ day-to-day lives. If it was all feasting, fighting, and lusting after gold, then I don’t find this period very interesting. But I think the problem is that the characters and their lives are not fully realized. I couldn’t help contrasting this novel with King Hereafter by Dorothy Dunnett, set a few centuries later, which has similar themes and story arc, but it is so much richer. Or, for that matter, The Long Ships, set a little nearer in time, about characters leading a similar life, but with a rollicking sense of humor.
whatmeread 
I liked this more than you did, but it’s about the history of my part of England (Northumbria) so it was of particular interest to me. I enjoyed it, but I agree that it doesn’t compare to King Hereafter. I must read The Long Ships soon!
Yes, I think you’d enjoy it! I’ve always wanted to visit Northumbria. I think Mary Stewart’s The Ivy Tree is set there, isn’t it?
I actually thought the historical context was very well described. Here is my own review: https://wordsandpeace.com/2014/09/15/book-review-and-giveaway-edwin-high-king-of-britain/
The historical context, yes, but no sense of the day-to-day life.