It is by reason of the pre-eminence of Arthur that we find gathered round him so many gods, all probably various tribal personifications of the same few mythological ideas. The Celts, both of the Gaelic and the British branches, were split up into numerous petty tribes, each with its own local deities embodying the same essential conceptions under different names. There was the god of the underworld, gigantic in figure, patron alike of warrior and minstrel, teacher of the arts of eloquence and literature, and owner of boundless wealth, whom some of the British tribes worshipped as Brân, others as Urien, others as Pwyll, or March, or Mâth, or Arawn, or Ogyrvran. There was the lord of an elysium—Hades in its aspect of a paradise of the departed rather than of the primeval subterranean realm where all thing’s originated—whom the Britons of Wales called Gwyn, or Gwynwas; the Britons of Cornwall, Melwas; and the Britons of Somerset, Avallon, or Avallach. Under this last title, his realm is called _Ynys Avallon_, “Avallon’s Island”, or, as we know the word, Avilion. It was said to be in the “Land of Summer”, which, in the earliest myth, signified Hades; and it was only in later days that the mystic Isle of Avilion became fixed to earth as Glastonbury, and the Elysian “Land of Summer” as Somerset.[420] There was a mighty ruler of heaven, a “god of battles”, worshipped on high places, in whose hands was “the stern arbitrament of war”; some knew him as Lludd, others as Myrddin, or as Emrys. There was a gentler deity, friendly to man, to help whom he fought or cajoled the powers of the underworld; Gwydion he was called, and Arthur. Last, perhaps, to be imagined in concrete shape, there was a long-armed, sharp-speared sun-god who aided the culture-god in his work, and was known as Lleu, or Gwalchmei, or Mabon, or Owain, or Peredur, and no doubt by many another name; and with him is usually found a brother representing not light, but darkness. This expression of a single idea by different names may be also observed in Gaelic myth, though not quite so clearly. In the hurtling of clan against clan, many such divinities perished altogether out of memory, or survived only as names, to make up, in Ireland, the vast, shadowy population claiming to be Tuatha Dé Danann, and, in Britain, the long list of Arthur’s followers. Others—gods of stronger communities—would increase their fame as their worshippers increased their territory, until, as happened in Greece, the chief deities of many tribes came together to form a national Pantheon.