The Pale Horseman — Bernard Cornwell

The last unvanquished piece of England, Wessex is eyed hungrily by the fearsome Viking conquerors. A dispossessed young nobleman, Uhtred is tied to the imperiled land by birth and marriage but was raised by the Danish invaders--and he questions where his allegiance must lie. But blood is his destiny, and when the overwhelming Viking horde attacks out of a wintry darkness, Uhtred must put aside all hatred and distrust and stand beside his embattled country's staunch defender--the fugitive King Alfred.