The unlikely king who saved England.

Down swept the Vikings from the frigid North. Across the English coastlands and countryside they raided, torched, murdered, and destroyed all in their path. Farmers, monks, and soldiers all fell bloody under the Viking sword, hammer, and axe.

Then, when the hour was most desperate, came an unlikely hero. King Alfred rallied the battered and bedraggled kingdoms of Britain and after decades of plotting, praying, and persisting, finally triumphed over the invaders.

Alfred's victory reverberates to this day: He sparked a literary...