sentences:  In the early part of the 12th century, John of Worcester had reason to believe that Eric ("Yrcus") was of royal Scandinavian stock ("Danica stirpe progenitum", a phrase used earlier for the Hiberno-Norse ruler of Northumbria, Sihtric Cáech).This appears to match with independent tradition from Norwegian synoptic histories and Icelandic sagas, which are explicit in identifying Eric of Northumbria as a son of the Norwegian king Harald (I) Fairhair.The skaldic poems ascribed to Egill Skallagrímsson may offer further reassurance that the sagas are on the right track, although doubts have been expressed about the date and integrity of the verses in the form in which they have survived.