Article from the BBC:
King of the southern Anglo-Saxon kingdom of Wessex and one of the outstanding figures of English history, as much for his social and educational reforms as for his military successes against the Danes. He is the only English monarch known as ‘the Great’.
Alfred was born at Wantage in Oxfordshire in 849, fourth or fifth son of Aethelwulf, king of the West Saxons. Following the wishes of their father, the sons succeeded to the kingship in turn. At a time when the country was under threat from Danish raids, this was aimed at preventing a child inheriting the throne with the related weaknesses in leadership. In 870 AD the Danes attacked the only remaining independent Anglo-Saxon kingdom, Wessex, whose forces were commanded by Alfred’s older brother, King Aethelred, and Alfred himself.