6Jackson, Kenneth Hurstone. The Oldest Irish Tradition: A Window on the Iron Age. Cambridge: Cambridge University Press, 1964. 44, note 1.
This entire note may be worth repeating: "I should emphasize that what I mean here is the historiasity of persons and events; for instance, Conn and Eoghan, kings of the north and south of Ireland respectively, reputed by the sages to have lived in the second century, are quite obviously legendary and indeed mythological characters, and the events in which they are said to have taken part are clearly bogus. The same is true of still later characters like Cormac mac Airt. It is probably not too much to say that the earliest figure whom we can regard with any confidence as at all historical is Niall of the Nine Hostages. Equally, then, the characters Conchobar and Cu Chulainn, Ailill and Medb and the rest, and the events of the Cattle Raid of Cooley, are themselves entirely legend and purely un-historical. But this does not mean that the traditional background, the setting, in which the Ulster cycle was built up is bogus; the whole of this lecture is intended to show that it is not."