Astrid Njalsdotter (or Ástríðr Njálsdóttir) of Skjalgaätten (also Aestrith) (11th century), was a Norwegian noblewoman who married Ragnvald the Old and became the ancestress of the Swedish Stenkil dynasty (c. 1060 – c. 1125).
[1] From other Norse sources it appears that Njal Finnsson was the son of Gunhild Halvdansdotter of the Skjalga family, a cognatic descendant of Harald Fairhair, the first king of Norway and an alleged scion of the Yngling dynasty.
In older historiography it was common to identify him with Ragnvald Ulfsson, a Swedish or Geatic Jarl who served under King Olof Skötkonung in the early 11th century.
According to the Norse sagas, Ragnvald Ulfsson was forced to flee Sweden after a dispute with the king, and was eventually established as Jarl of Staraya Ladoga.
[3] The German ecclesiastic historian Adam of Bremen writes that Stenkil was either the stepson (privignus) or nephew (nepos) of the previous Swedish ruler Emund the Old (c. 1050-c.