Wikipedia
In Irish mythology, Tuireann ( Old Irish: Tuirenn or Tuirill Biccreo) was the father of Creidhne, Luchtaine and Giobhniu by Brigid.
His other sons, by his daughter Danand, included Brian, Iuchar and Iucharba, who killed Lugh's father Cian. After Lugh had taken his elaborate revenge, Tuireann died of grief over their graves.
He is stated in various portions of Lebor Gabála Érenn to be the same person as Delbáeth Mac Ogma, who is also credited as the father of Brian, Iuchar and Iucharba. He is likely related to the Gaulish deity Taranis and thence to Thor of the Scandinavians.
His name points to a Proto-Indo-European root which gives us words for thunder or related concepts even today, for instance the Old English "Thunores Dæg" (Thursday), as well as dedication to the god and tórnach, the Irish word for thunder.