Alfred the Great necessary, that each man keep carefully his oath and his pledge" which expresses a fundamental tenet of Anglo-Saxon law. Alfred devoted considerable attention and thought to judicial matters. Asser underscores his concern for judicial fairness. Alfred, according to Asser, insisted upon reviewing contested judgments made by his ealdormen and reeves and "would carefully look into nearly all the judgements which were passed [issued] in his absence anywhere in the realm to see whether they were just or unjust". A charter from the reign of his son Edward the Elder depicts Alfred as hearing one such appeal in his chamber while
Æthelwold ætheling sons in succession. King Æthelbald died in 860, and King Æthelberht in 865; Æthelwold's father, Æthelred, then succeeded to the throne. In the same year the Viking Great Heathen Army invaded England. Within five years they had conquered Northumbria and East Anglia, and forced Mercia to buy them off. In late 870 the Vikings invaded Wessex, and in early 871 they fought armies under Æthelred and Alfred in four battles in quick succession, the last two of which Wessex lost. Æthelred died shortly after Easter that year, leaving young sons. Primogeniture was not established in this period, and it was