Dr Alexander Bugge has pointed out for us how many characteristic features of Viking life find their closest parallel among uncivilised peoples of the ancient or of the modern world. Their cruelty in warfare finds illustration in their custom of exposing the heads of their enemies outside their camps and towns, or in the strange picture given us in some Irish annals of Danes cooking their food on the field of battle on spits stuck in the bodies of their fallen foes. The custom of human sacrifice was fairly common, while that of cutting the blood-eagle in the back of the fallen foe is well known from the vengeance for their father taken by the sons of Ragnarr Loðbrók. Children were not spared in warfare and were often tossed on the spears of their foes. A curious survival of primitive habit is found in the famous Berserk fury, when men in the heat of battle were seized with sudden madness and, according to the popular belief, received a double portion of strength and lost all sense of bodily pain. There is of course much that is superstitious in this idea, but it finds its parallel in the "running amok" of the races of the Malay peninsula. Side by side with these traits of primitive barbarism we find certain well-developed forms of culture, an extensive commerce, a mastery of the whole art of shipbuilding, and great artistic skill, shewn not only in articles of personal adornment but also in the sculptured memorial stones to be found from Gothland in the East to Man in the West. In warfare their cavalry were skilled, and they understood the construction of siege engines with the whole art of fortification. Above all the Northmen had a genius for law, and few early communities shew their aptitude in the making of laws or such strictness in their observance.
The passage from heathendom to Christianity this critical period is in some ways even more interesting. We have already seen how in the middle years of the ninth century Christianity was preached in Denmark and Sweden, but it had little effect on the main body of the nations concerned. The best evidence of this is to be found perhaps in the fact that it is in all probability to the ninth and tenth centuries that we owe the poems of the elder Edda, the main source of our knowledge of Old Norse mythology and cosmogony. It is true, no doubt, that in some of these poems we find a note of detachment, touches of irony and even of burlesque, which remind us that the belief in the old gods is passing away, but in the great body of those which deal with the world of the Aesir, there is no question of fading beliefs or of insincere statement. The greater number of the Vikings were undoubted heathen, and like the impious Onlafbald when defying the power of St Cuthbert would have sworn by their great gods Thor and Othin. When the Danes made peace with Alfred in 876 they swore an oath on the holy ring, which would be found on the altar of every heathen temple: such a ring sacred to Thor was taken by the Irish from a temple in Dublin in 996. There was a grove sacred to Thor just north
