Dublin is the capital of Ireland. It was closely connected to the Isle of Man through trade, administration, and the movement of people, particularly during the eighteenth century when Manx smuggling severely affected Irish customs revenues. The annuity of two thousand pounds granted to the Duke of Atholl after the Revestment was charged on the Irish revenues.

The Norse kings of Man held Dublin as well. Godred Crovan conquered the kingdom of the Isles, subduing Dublin, Leinster and parts of Scotland, and after reigning sixteen years died in Islay leaving three sons. The Manx historians observe that because the Scandinavian rulers of that period were sometimes driven out of Northumbria and sometimes out of Dublin, Man must have been a convenient headquarters for them, and they note the intervals when Dublin was again subject to Irish rulers.

The scholarly traffic ran through Dublin too. The Irish Archaeological Society, founded there in 1840 with Prince Albert as its patron and the Duke of Leinster as president, published the editions of the Irish genealogies and customs that the Manx antiquaries used for the Norse and Gaelic centuries of their own history.