Alfred was born in 849 in the village Wanating in what is now Wantage, Oxfordshire, the youngest son of King Aethelwulf of Wessex and his first wife, Osburga. Aethelwulf was a devout Christian, a trait that would reflect in Alfred's life. It was during his youth that [[Bishop]] Asser tells the story of how as a child Alfred won a prize of a volume of poetry in English offered by his mother to the first of her children able to memorize it. Legend also has it that the young Alfred spent time in Ireland seeking healing. He was troubled by health problems throughout his life although today he is often portrayed as a great warrior who was noted more for his intellect.

It was following the accession of his third brother, Aethelred of Wessex, in 866, that Alfred's public life began. Fighting beside his brother Aethelred, in 868, Alfred fought unsuccessfully attempting to keep the invading Danes, led by Ivar the Boneless, out of the adjoining Kingdom of Mercia. Then in late 870, with the arrival of the Danes in his homeland, Alfred became involved in nine battles with varying outcomes. Thus, the year 870 was the low-water mark in the history of the Anglo-Saxon kingdoms. Only Wessex remained to resist as all the other kingdoms having fallen to the Vikings.