This is number three in Cornwell's series about Alfred the Great. It focuses primarily on the narrator, Uhtred, and his quest for revenge over his own disinheritance and the murder of his foster-father.
It's a great story. Plenty of adventure and excellent characters. Although a lot of the events that occur are supremely unlikely, Cornwell has a way of making them so much part of the flow that I never find myself questioning them.
I really am stunned at how likeable and interesting he has drawn the character of Uhtred, as well. He's a vicious murderer and warrior, and yet his sense of honour and other virtues make you like him regardless. Wonderful stuff.
On top of that, it takes you into the world of tenth century Britain very convincingly. A good escape from the travails of modern life (as long as you are just reading a book about it, anyhow).