Hakon sveinsson dating
The reign of King Harald is reported both in the Sagas and the Historia as improbably long and his descendants as improbably numerous.
For example, according to the Historia Norwegie he reigned for 73 years and had sixteen sons.
As far as the earliest sub-period is concerned, the early ancestry of the Norwegian kings is shrouded in mystery and confused by legendary descents.
The main primary sources which have been used in the preparation of the present document are English translations of Snorres Heimkringsla series of Sagas.
In addition, few factual inconsistencies can be identified within either the Historia Norwegi or the Heimskringla series of Sagas with respect to this period: the genealogies of the Scandinavian rulers reconstructed from these sources fit neatly together and their chronology appears robust.
This contrasts with the shaky chronology of the early rulers of Orkney described in Orkneyinga Saga, which provides genealogical details which purport to link the successive jarls of Orkney into a single family whose ancestry is traced back to Earl Rognwald the Powerful, a leading supporter of Harald I "Hrfagre" King of Norway.
Firstly, Ari orgilsson, in his extant slingabk, indicates tantalisingly that the book is a revision of an earlier version minus the genealogies and kings lives, without indicating the date of that early version or any more details.
Secondly, a poem dated to  reviews ten Norwegian kings from Harald I "Hrfagre/Harfagri/Fairhair" forwards as Smundr inn frdi [the Wise] told. However, if the hints are correct, it is possible that the precursors to the surviving primary sources dated from the mid- to late-11th century and were roughly contemporary with the reigns of Kings Harald III and Olav III (from 1047 to 1093), which may give some comfort about the factual accuracy of the Saga and Historia narratives relating to the families of these kings.