Ethelbert (also Æthelberht), king of Wessex (860-866) succeeded his elder brother Ethelbald. He had the misfortune to rule at the time of increased Danish incursions into many parts of England. It is recorded that his forces had a victory during the first year of his reign, but by 865 the Danes were encamped permanently at Thanet (north-east Kent) and being offered tribute for a truce. Outside his kingdom, in northern East Anglia and Northumbria, cities were falling, not to raiding parties, but to armies of occupation. By the year of his death, they had moved down to Nottingham. He was succeeded by his younger brother, Ethelred I.
Reference: “Anglo-Saxon Chronicle” trans. Anne Savage