Baltic tribes, and the Slavs all had holy groves within the forest where the thunder god was worshipped. Grimm suggested that the connexion between the god and the oak was a practical one, because the oak was the tree most often struck by lightning. The emphasis, however, should probably be laid on the fact that when a great oak is struck by lightning, the sight of its destruction is something unforgettable. A vivid description of such a happening given by Tolstoy in
… Suddenly there was a glare of light, the whole earth seemed on fire, and the vault of heaven cracked overhead. Opening his blinded eyes, to his horror the first thing Levin saw through the thick curtain of rain between him and the woods was the uncannily altered position of the green crest of a familiar oak in the middle of the copse. ‘Can it have been struck ?’ The thought had barely time to cross his mind when, gathering speed, the oak disappeared behind the other trees, and he heard the crash of the great tree falling on the others.
There is little doubt that this is based on observation, and that Tolstoy had seen an oak falling in a storm. His impression that the heavens had opened and that fire from them was descending on to the earth is significant. As a channel through which the power of the sky god might reach down to the world of men, it is understandable that the mighty oak tree, itself a splendid symbol of age, strength, and endurance, came to be considered specially sacred to the Thunderer.
Groves which the Germans held sacred to the gods are mentioned by Tacitus at the end of the first century. Later on, a number of Christian missionaries – Boniface, Jerome, Bishop Otto, Willebrord–counted the felling of a tree sacred to a heathen god among their achievements in the cause of Christ. There is mention of ‘Jupiter’s Oak’ more than once. The Prussians remained heathen long after Germany as a whole had been converted, and in the sixteenth century writers who visited them described sacred woods in which they made sacrifices and sacred springs which Christians were not allowed to approach. The chief of these sanctuaries was at Romove, where there was a holy oak, in whose trunk were placed images of the gods. Before that of the thunder god, Perkuno, was a fire which was never allowed to go out. The fire was surrounded by curtains, forming a shrine which only the high priest might enter to commune with Perkuno. The name of this god is linked with the Latin word for oak,
In Iceland there were no great oaks, and thus the link between the thunder god and the trees has become blurred in the Icelandic sources. But the link was there all the same, and we can discern it in the custom of the settlers to take the oak pillars of Thor’s temple with them to Iceland. The pillar, as we have seen, was sacred to the god, and there seems good reason to believe that this was because the pillar represented the sacred tree, in which the power of the god dwelt. In one case in
The high-seat pillar formed a support of the hall or temple, and a resemblance between this and the ‘lucky’ tree, which stood beside the house, and on whose well-being the luck of the family depended, seems a reasonable assumption. In the story of King Volsung, this tree formed a living support to his hall, and there are still a few houses remaining in the British Isles where the building has been supported by a great tree in the centre.1 The ‘lucky’ family tree was well-known at one time in Norway, Sweden, Denmark, and Germany. A folk custom still known in England is the raising of a branch from the roof or chimney of a house when the builders have finished the roof (with free drinks all round). One reason given for this is that the house will afterwards be safe from lightning if this ceremony is carried out. In the same way we may assume that pillars hallowed to Thor would protect the dwelling which they supported from the terrors of the storm. Also, like the sacred tree in the forest, they marked the most holy place, where the worshipper might approach the thunder god and learn his will.
5.
Evidence leads us to believe that the cult of Thor was a vigorous one in the north, and that it continued to be so until the close of the heathen period. There are two indications of its widespread influence on the lives of men: the large number of children in Scandinavia who were named after the god, and the many places called after him. In Dublin the Irish referred to the Viking settlers as ‘people of Thor’. We find men giving respectful and at times devoted allegiance to the god of thunder, in particular among the sturdy Norwegian landowners of good stock though not of royal blood, the independent settlers in Iceland and Ireland, and the adventurers who ‘trusted in their own strength and might’. It was in fact a cult which attracted those accustomed to make their own decisions and resentful of too much authority from above.
Thor was the sky god, called upon to hallow and protect the various aspects of men’s lives in the community. When we turn from this conception to the picture of the hammer god of myths, there seems at first sight a contradiction. Thor in Asgard spends much of his time ‘out killing trolls’, or arriving home to dispose of some unwelcome giant who has penetrated the realm of the gods. His adventures are tinged with comedy, and he appears as a being of great strength and uncertain temper, who in moments of crisis simply reaches for his hammer. Myths may be simplified, rationalized, or twisted into comedy, particularly when, as in the case of the myths retold by Snorri, they are recorded after the end of the heathen period. Nevertheless much may still be learned of the nature of a god by the adversaries whom he encounters, and this is true of Thor.
Thor’s battles are for the most part with the frost-giants and giantesses, such as Hrungnir, Thrym, Hymir, Geirrod, and their broods. Sometimes they try to lure him into their realms unarmed, but for the most part he goes deliberately to seek them, and kills them without much difficulty once it comes to a direct trial of strength. His most terrible adversary however is the World Serpent, who lies coiled round the earth. Thor’s attempt to raise him, when he appears in the form of a great grey cat, is well known; and is a vivid incident in a very amusing tale. But the story of the fishing expedition with the giant Hymir, when Thor drew up the serpent from the ocean depths, was a myth which appears to have been taken seriously. It was at all events well known to poets of the ninth century, for we have four poems all earlier than A.D. 1000 which describe the fishing in some detail:
The poem
None of the poems make it clear whether the battle between the god and the monster was a conclusive one, and whether we are to regard the hammer-blow struck at the serpent as its bane. In Snorri’s prose account, based on