 It is not common to believe in the detailed accuracy of the historical narrative and historians tend to see little to no historical truth behind the first few sagas, however, they are still seen by many as a valuable source of knowledge about the society and politics of medieval Norway.The factual content of the work tends to be deemed more credible where it discusses more recent times, as the distance in time between the events described and the composition of the saga was shorter, allowing traditions to be retained in a largely accurate form, and because in the twelfth century the first contemporary written sources begin to emerge in Norway.Whereas prior to "Heimskringla" there seems to have been a diversity of efforts to write histories of kings, Snorri's "Heimskringla" seems thereafter to have been the basis for Icelandic writing about Scandinavian kings, and was expanded by scribes rather than entirely revised.