According to the mythological accounts, Frey was the son of Njörd and brother of Freyja. He had great personal beauty in addition to his divine powers. 'He rules over rain and sunshine and the produce of the earth, and it is good to call on him for peace and plenty. He also has power over the prosperity of men.' He was believed to own the ship _Skíðblaðnir_, and to ride on the boar _Gullinbursti_ (Golden-bristle). This association of Frey with the boar appears also in the following passage of one of the mythical sagas (_Hervarar Saga_): 'King Heidrek sacrificed to Frey; he should give to him the largest boar that could be got. They considered it so holy, that over its bristles they took an oath about all important matters. That boar was sacrificed by way of an atonement; on Christmas eve it was led into the hall before the king, and men then laid their hands on its bristles and made their vows.' In another and earlier mention of the _sónargöltr_ (boar of atonement), however, it is not stated that the practice was connected with the cult of Frey, and in the absence of direct historical evidence the reality or significance of the rite remains doubtful. As mentioned above, the mythology regarded Frey as the son of Njörd (_Njörðr_), a god of whom very little is really known. It has been supposed that the _Nerthus_, mentioned by Tacitus as being worshipped in common by a number of Germanic tribes, is the same as Njörd, but the fact that Tacitus speaks of Nerthus as a goddess and explains the name as meaning Mother Earth, makes the identification a very doubtful one. According to Snorri, Njörd 'rules over the course of the wind and calms the sea and fire. He is to be called on for voyaging and fishing. He is so rich and wealthy that he may give lands and treasure to whom he will.'