Complex sentence: Earl Godwin's father was certainly named Wulfnoth, a relatively uncommon name, and in the view of Frank Barlow, the evidence is indisputable that he was the same person as Wulfnoth Cild, a thegn in Sussex.
Split into simpler sentences: Earl Godwin's father was certainly named Wulfnoth, a relatively uncommon name. He is thus assumed to be the same person as Wulfnoth Cild, a thegn in Sussex.