The most probable, and only adequate explanation, is given by Professor Rhys, who considers that the fames of two separate Arthurs have been accidentally confused, to the exceeding renown of a composite, half-real, half-mythical personage into whom the two blended.[359] One of these was a divine Arthur, a god more or less widely worshipped in the Celtic world—the same, no doubt, whom an _ex voto_ inscription found in south-eastern France calls _Mercurius Artaius_.[360] The other was a human Arthur, who held among the Britons the post which, under Roman domination, had been called _Comes Britanniæ_. This “Count of Britain” was the supreme military authority; he had a roving commission to defend the country against foreign invasion; and under his orders were two slightly subordinate officers, the _Dux Britanniarum_ (Duke of the Britains), who had charge of the northern wall, and the _Comes Littoris Saxonici_ (Count of the Saxon Shore), who guarded the south-eastern coasts. The Britons, after the departure of the Romans, long kept intact the organization their conquerors had built up; and it seems reasonable to believe that this post of leader in war was the same which early Welsh literature describes as that of “emperor”, a title given to Arthur alone among the British heroes.[361] The fame of Arthur the Emperor blended with that of Arthur the God, so that it became conterminous with the area over which we have traced Brythonic settlement in Great Britain.[362] Hence the many disputes, ably, if unprofitably, conducted, over “Arthurian localities” and the sites of such cities as Camelot, and of Arthur’s twelve great battles. Historical elements doubtless coloured the tales of Arthur and his companions, but they are none the less as essentially mythic as those told of their Gaelic analogues—the Red Branch Heroes of Ulster and the Fenians.