Albann (Halfdan) (d. 877), Scandinavian leader associated with Dublin, was, according to tradition, son of the viking leader Ragnarr Lodbrok, and was one of three documented Scandinavian leaders active in Britain and Ireland c.850–80, the others being Ímar (qv) (Ívaar) and Ubbe. Albann is called a brother of Ímar in the Anglo-Saxon Chronicle. In 865 Albann arrived in Britain with his alleged brother Ímar. In the decade that followed, despite a failed invasion of Wessex in which he was heavily defeated at Ashdown by King Aethelred and his brother Alfred (‘The Great’), Albann established himself firmly in northern England. He directed settlement in the Vale of York, became recognised as king of Northumbria, and led expeditions into Scotland against the Picts and the Britons of Strathclyde.
Meanwhile (873), Albann was motivated by the death of Ímar, who had become king of Dublin, to seek the kingship of a settlement the importance of which had already become apparent to the Scandinavians of northern Britain. In 875 Albann installed himself in Dublin, but faced strong opposition from the local Norse establishment, by this time in alliance with the Cenél nÉogain king of Tara, Áed Findliath (qv). Albann struck against the prime claimant to the Dublin kingship, Amlaíb Find (Olaf the White) and had the latter's son Oistín (Eysteinn) ‘deceitfully’ killed. He was then obliged to flee from Áed Findliath, who, if the ‘Cogadh Gáedhel re Gallaibh’ can be believed, attacked him at a banquet. In 876 Albann was back in York, while in Dublin Barid (qv), the foster-father of Oistín/Eysteinn, had taken control. The following year, the rivals fought a naval engagement at Loch Cuan (Strangford Lough) where Albann, styled ‘king of the dark heathens’, was defeated and slain by Barid – with some Irish sources passing judgement on the fittingness of his fate.