Halfdan wins the Kingdom of Dublin

So OTL Halfdene, more commonly Halfdan, early after becoming King of Yorvik sailed to claim Dublin, the kingdom likely previously ruled by his brother Ivar the Boneless, but died trying to take it.
So ATL he succeeded. What are the repercussions?
 
There’s so little reliable information on Norse figures like Halfdan that it’s hard to tell what the repercussions would have been. We barely know anything about the him, and as far as I know he had no descendants. If I had to guess, this would essentially have no foreseeable effect on the British Isles as a whole, as early Norse kingdoms were unstable and shifted dynasties often OTL.
 
There’s so little reliable information on Norse figures like Halfdan that it’s hard to tell what the repercussions would have been. We barely know anything about the him, and as far as I know he had no descendants. If I had to guess, this would essentially have no foreseeable effect on the British Isles as a whole, as early Norse kingdoms were unstable and shifted dynasties often OTL.
We know the kings after him were at least nominally Christian. And one of the reasons for no descendants was dying trying to take Dublin.
An early union across the Irish sea would at least prompt something wrt Gwynnedd and relations with remnant Mercia and Wessex.
 
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