such goddesses as Morrigan and Brigit, the
threefold name of Dagda's wife, or the fact that Arm, Danu, and Buanan
are called "mothers," while Buanan's name is sometimes rendered "good
mother," may suggest that such grouped goddesses were not unknown. Later
legend knows of white women who assist in spinning, or three hags with
power over nature, or, as in the _Battle of Ventry_, of three
supernatural women who fall in love with Conncrithir, aid him in fight,
and heal his wounds. In this document and elsewhere is mentioned the
"_sid_ of the White Women."[246] Goddesses of fertility are usually
goddesses of love, and the prominence given to females among the _side_,
the fact that they are often called _Be find_, "White Women," like
fairies who represent the _Matres_ elsewhere, and that they freely offer
their love to mortals, may connect them with this group of goddesses.
Again, when the Milesians arrived in Ireland, three kings of the Tuatha
Dea had wives called Eriu, Banba, and Fotla, who begged that Ireland
should be called after them. This was granted, but only Eriu (Erin)
remained in general use.[247] The story is an aetiological myth
explaining the names of Ireland, but the three wives may be a group like
the _Matres_, guardians of the land which took its name from them.

Brian, Iuchar, and Iucharba, who give a title to the whole group, are
called _tri dee Donand_, "the three gods (sons of) Danu," or, again,
"gods of _dan_" (knowledge), perhaps as the result of a folk-etymology,
associating _dan_ with their mother's name Danu.[248] Various attributes
are personified as their descendants, Wisdom being son of all
three.[249] Though some of these attributes may have been actual gods,
especially Ecne or Wisdom, yet it is more probable that the
personification is the result of the subtleties of bardic science, of
which similar examples occur.[250] On the other hand, the fact that Ecne
is the son of three brothers, may recall some early practice of
polyandry of which instances are met with in the sagas.[251] M. D'Arbois
has suggested that Iuchar and Iucharba are mere duplicates of Brian, who
usually takes the leading place, and he identifies them with three kings
of the Tuatha Dea reigning at the time of the Milesian invasion--
MacCuill, MacCecht, and MacGrainne, so called, according to Keating,
because the hazel (_coll_), the plough (_cecht_), and the sun (_grian_)
were "gods of worship" to them. Both groups are grandsons