In 860, two years before ascending the throne of Wessex, Alfred married Aelhswith of Gaines and Mercia. During this period Viking raiders invaded and plundered England. Losing the battle of the Viking invasion of 878 by the Danish 'Great Army', Alfred was forced into hiding. He returned to the battlefield that same year at Edington where he defeated the Vikings.

Alfred went on to build strong defenses, incorporating forts and building a fleet of ships, and he initiated required military service for free men in his kingdom. During his rule, Alfred unified Wessex, annexed part of Mercia, and brought the princes of Wales under his authority.

Recognized as a Christian King of England, Alfred strongly promoted literacy, education, and assembled scholars to promote learning. When Alfred died in 899, he left Wessex stronger and its kingship better established.