1 The Naval Power of Norse Dublin Poul Holm In the ninth to twelfth centuries the Dublin fleet was one of the most formidable war machines in the Irish Sea area. I shall analyse the annalistic and archaeological evidence for Hiberno-Norse naval power in Dublin around 1000 AD. Drawing on comparative information from Scandinavia and England, I shall consider the manpower needed for the fleet, and the financial and monetary implications of the size of the fleet. 1 Dublin in 1014 – in decline or going strong? By Christmas of 1013 it may have seemed likely that all of Britain and Scotland would fall under Norse supremacy within the next few months. In England, King Svein Forkbeard had all but conquered the country except for London. By Yuletide, according to Njál’s saga, King Sigtryggr Silkenbeard of Dublin feasted at Jarlshof in Orkney with Jarl Sigurd. Their plan seems to have been to use the unrest building in the north-east of Ireland against the newly established high-kingship of Brian Bóruma and to assemble a large army of Norse mercenaries with the seditious men of Leinster against the high-king. King Brian was well aware of the threat from Dublin which he had unsuccessfully besieged in the autumn of 1013. But whatever high hopes may have been nurtured at the Orkney jarls’s feast in Jarlshof, a few months later the tables had turned. King Svein died in February 1014 and the Danish hold on England seemed to crumble. In April, on Good Friday, Brian Bóruma’s men defeated the men of Leinster, Orkney and Scottish Isles. While the Danes eventually reasserted their power in England, the Dublin Scandinavians gave up any larger plans they may have had for Ireland. How should we understand events on the Dublin side of the Irish Sea? More specifically, did the Norse of Dublin and the Irish Sea area have the military power to even contemplate a conquest of Ireland like their Danish colleagues were clearly attempting? The answer to this question is crucial for any evaluation of ninth- to eleventh-century Irish history and for our assessment of Scandinavian power in Western Europe. However, the written evidence, most often considered by historians, allow for two very different 1 A version of this paper was presented to the American Society for Irish Medieval Studies conference in 2011. See also Colmán Etchingham, ‘Skuldelev 2 and Viking-age ships and fleets in Ireland’, this volume, pp###. Forthcoming in Clerics, kings and Vikings: essays on medieval Ireland in honour of Donnchadh Ó Corráin , Dublin, Four Courts Press, 2015