The life-producing, fruit-bearing earth’s female representative among the powers, the goddess Frigg, has, as I shall demonstrate below, mythological prerequisites that go back to the Proto-Indo-European era; but, as a pronounced epic personality, she belongs to the same period that gave rise to Njörd, Frey, and Freyja. In order not to perpetuate an error that lies close at hand with reference to the name Frigg, we ought to carefully distinguish between this epithet, which is merely one among the many she bore, and the personality of the goddess. It is by no means certain that the name Frigg and its German equivalent Friia were fixed on her at all times and by all Germanic tribes. On the contrary, there are reasons to assume that this was not the case.
Friia, which stands in etymological connection to the proto-Germanic frija and Sanskrit priya, dear, friendly, is an epithet that can easily be applied to Freyja and actually seems to have been used of her in the German designations for Friday, Frîatac, Frîgetac, which correspond to the Latin dies Veneris, the goddess of love’s day, Freyja’s day. The name Friia, Frigg (compare Anglo-Saxon frigu, love) originally was, and among certain Germanic tribes presumably always has been, an epithet applied to Odin’s wife as well as Frey’s sister, on the matronly queen of the world and on the young goddess of love, who however, in other respects, are as completely different from one another in personality as Hera-Juno and Aphrodite-Venus. To draw the conclusion that these goddesses did not appear as different personalities in the Germanic imagination because the epithet friias was common to Odin’s wife and Frey’s sister is logically unjustified and meets with psychological impossibilities.
Older designations of Odin’s wife and Thor’s mother, exclusively applied to her, are Fjörgyn, Hlóðyn, Jörð, and Nirdu-Nerthus. Thor is mögr Hlóðynjar, Jarðar burr, and Fjörgynjar burr.7 One learns with certainty from the Nordic sources (Lokasenna, Saxo, Prose Edda) that the Scandinavians ultimately fixed the name Frigg on this Fjörgyn. The name Nirdu (Nerthus in Tacitus) is an older feminine form of the name Njörd.8 Njörd is, as mentioned, the god of the Ocean and navigation; Fjörgyn-Frigg is the goddess of the lifeproducing earth. In the Germanic theology, the Ocean and the Earth have been regarded as siblings, both born of the mother of the gods, Night-Aditi. The memory of this is still preserved in Gylfaginning.
The commonality of names between the siblings Njörd and Nirdu has its parallel in the commonality of names between the siblings Frey and Freyja and therefore ought not come as a surprise. In Norse mythology, the goddess Jörd appears with the character she has had as far back as one can trace a distinguishing narrative about her. Tacitus (Germania 40) clearly identifies Nerthus with her: Nerthum, id est, Terram matrem (―Nerthus, who is Mother Earth‖). He relates that the Langobardians and some of their neighbors worship her in common and believe that she ―intervenes in matters that touch human affairs and the fate of nations.‖
The History of the Langobardians explains why the Langobardians specifically devoted their foremost adoration to her and believed her to intervene in their nation’s fate when it says that the god of heaven’s wife, Wodan’s wife, Frea, persuaded Wodan in a cunning manner to give the Langobardians victory over their opponents, the Vandals. This tale is an illustration of Tacitus’ statement, and Tacitus’ statement explains it. The connection of both sources to one and the same mythic episode is obvious. Of no Germanic goddess, with the exception of Frigg, is anything similar related. And because Tacitus collected a great part of his mythic information regarding the Teutons from sources that went back to Christ’s birth and the era surrounding it, we thus have evidence as far back as that time that Nerthus, Njörd’srelative, is identical with Mother Earth and Wodan’s wife, Frea-Frigg.
The description Tacitus provides in the same chapter of Germania regarding the ceremony with which she was worshipped corresponds to a Swedish ceremony described in Ögmundar þáttur dytts, (Flateyjarbók I, 335) in which Frey, her brother’s son, was worshipped. Since both gods are Vanir divinities and, in regard to the natural phenomena they represent, both stand in the same relationship to one another as the nourishing earth to the harvest, a mutual similarity can be presumed about these ceremonies. The identity of Terra Mater and Frigg is additionally confirmed in the 2nd chapter of Germania, where it says that Terra Mater was mother to Tuisco, the son of Tívi. In the first part of this work I have demonstrated that Tuisco is the same as Frigg’s son, Jarðarburr. 9
On the this subject we strongly advise the ultimate work of research developed by William P Reaves :