In this course of development from the purely mythical to the historical, the saga may approach no more closely to historical reality than does the purely mythical tale. But while this may be the case, it is nevertheless true that the saga more and more approximates to that which is _historically possible_. Moreover, it is not those sagas which centre about an historical hero that are particularly apt to be free from elements of the original märchen. Very often the reverse is true. An original märchen-hero may become the central figure of an historical saga, and, conversely, the account of an historical personality may become so thoroughly interwoven with märchen-like tales of all sorts that history entirely disappears. A striking antithesis of this sort occurs in Germanic mythology. Compare the _Dietrich_ saga with the later development of the _Niebelungen_ saga in the form rendered familiar by the _Niebelungenlied_. Siegfried of the _Niebelungen_ saga originates purely as a märchen-hero; Dietrich of Bern is an historical personage. But, while the _Niebelungenlied_ incorporates a considerable number of historical elements--though, of course, in an unhistorical combination--the Dietrich of the saga retains little more than the name of the actual king of the Goths. There are two different conditions that give rise to sagas. In the first place, historical events that live in folk-memory assimilate materials of ancient märchen and sagas, and thus lead to a connected hero saga. Secondly, an impressive historical personality stimulates the transference of older myths as well as the creation of others, though these, when woven into a whole, resemble a märchen-cycle rather than a hero saga proper.