If O'Loideahn is the root of the Irish branch of Luddens who are by and large from the West(beyond the Pale,)is it not unlikely that the Ludden name arrived in Ireland with the people who built the Pale. The Norman French invaders of Ireland were of Scandinavian descent so it is possible that a Lodden or two were amongst them but they would be confined to the Pale (the area of Norman French settlement) for a good while after the first incursions into Ireland and contact with the Irish would have been discouraged (they were regared by the Norman French as "little more than animals"). In my family,legend has it that Ludden derives from the same root as Leyden in Holland, or London(Lugdunum)both of which have their origins in the worship of the Celtic god Lug or Lud (Lug of the Silverhand). Ludden research is however filled with diversions. In Yorkshire close to the towns of Halifax and Todmorden are two villages called Luddenden and Luddenden Foot which appear to have no Celtic connections at all as this is one of the areas where the Celtic tribes were forced to move West by the Roman occupation of Britain. My own family is said to originate from the West of Ireland but I cannot find much information beyond my paternal Grandfather, Ernest Ludden who died in the 1930's in Salford, Lancashire.
There do not seem to be many British Ludden's contributing to these pages but if I have any relations in the US or elsewhere I'd like to hear from you.