Reginald King of Waterford and York is also known as "King of All the Foreigners of Ireland and England".
Following the expulsion of the Viking warrior class from Ireland, after 902 there were several failed attempts to re-establish bases in Ireland.
In 917, after 15 years in exile, Ivar the Boneless’s grandsons, Reginald and Sitric, assembled men and fleets of ships to invade Ireland. They faced two major obstacles – the native Irish, and the Dark Foreigners or Danes, their Viking enemies who had, in 914 under the leadership of Ottar, established themselves at Woodstown in Waterford harbour.
So when Reginald arrived in Waterford harbour, sailing up-river to Woodstown he chose instead to occupy a new site. He built a royal fort at a point where the river Suir is joined by a small tributary – the John’s River – the site of present-day Waterford city.
Now he could essentially trap Ottar at Woodstown. Reginald’s strategy worked. Ottar was subdued and Woodstown survived for only a decade or two after this.
Reginald went on to gain control over Dublin and by 918, at the head of a huge fleet from Waterford and Dublin, he also established control over York and Northumbria in England.
Reginald was the first in a line of Norse kings at York, or Yorvik, which ended only with the death of Eric Harladsson (Bloodaxe) in 954. In York, Reginald minted coins emblazoned with the hammer of Thor, the Viking god of thunder.