Bernard Cornwell's The Last Kingdom is a great book for anyone wanting to get a feel for the ninth century - in particular what it was like for the Saxons living there and having to deal with invading Danes (Vikings), who were trying to settle and do essentially what the Saxons had done a couple of centuries before to the earlier inhabitants.
While the main character and narrator, Uhtred, is but a boy at the beginning, our hero is Alfred the Great (the only British king ever to be called 'the Great'). I'm quite familiar with Alfred's history and life and how he emulated Charlemagne in many ways, and it's really enjoyable to see this well researched, fictional account from one of my favorite authors, and to see these historical characteristics in the people in the novel.
Though Bernard Cornwell isn't the most in depth of historical fiction writers, and his characters aren't always fully developed real people, he still does the job well, just as he did with his Grail series set in the Later Middle Ages, and his Arthur series. The Last Kingdom is the kind of book that anyone can pick up and enjoy without getting confused along the way by weighty history or jargon. Next in the series are
The Pale Horseman and
Lords of the North.