e as all myths do,
increasing as time went on, and the historical nucleus, if it ever
existed, was swamped and lost. Throughout the saga the Fians are more
than mere mortals, even in those very parts which are claimed as
historical. They are giants; their story "bristles with the
supernatural"; they are the ideal figures of Celtic legend throwing
their gigantic shadows upon the dim and misty background of the past. We
must therefore be content to assume that whether personages called
Fionn, Oisin, Diarmaid, or Conan, ever existed, what we know of them now
is purely mythical.

Bearing in mind that they are the cherished heroes of popular fancy in
Ireland and the Scottish Highlands, we have now to inquire whether they
were Celtic in origin. We have seen that the Celts were a conquering
people in Ireland, bringing with them their own religion and mythology,
their own sagas and tales reflected now in the mythological and
Cuchulainn cycles, which found a local habitation in Ireland. Cuchulainn
was the hero of a saga which flourished more among the aristocratic and
lettered classes than among the folk, and there are few popular tales
about him. But it is among the folk that the Fionn saga has always been
popular, and for every peasant who could tell a story of Cuchulainn a
thousand could tell one of Fionn. Conquerors often adopt beliefs,
traditions, and customs of the aboriginal folk, after hostilities have
ceased, and if the pre-Celtic people had a popular hero and a saga
concerning him, it is possible that in time it was accepted by the Celts
or by the lower classes among them. But in the process it must have been
completely Celticised, like the aborigines themselves; to its heroes
were given Celtic names, or they may have been associated with existing
Celtic personages like Cumal, and the whole saga was in time adapted to
the conceptions and legendary history of the Celts. Thus we might
account for the fact that it has so largely remained without admixture
with the mythological and Cuchulainn cycles, though its heroes are
brought into relation with the older gods. Thus also we might account
for its popularity as compared with the Cuchulainn saga among the
peasantry in whose veins must flow so much of the aboriginal blood both
in Ireland and the Highlands. In other words, it was the saga of a
non-Celtic people occupying both Ireland and Scotland. If Celts from
Western Europe occupied the west of Scotland at an early date, t