The personality of Fionn is also connected with the rebirth idea.  In one story, Mongan, a seventh-century king, had a dispute with his poet regarding the death of the hero Fothad.  The Fian Caoilte returns from the dead to prove Mongan right, and he says, “We were with thee, with Fionn.”  Mongan bids him be silent, because he did not wish his identity with Fionn to be made known.  “Mongan, however, was Fionn, though he would not let it be told."[1198] In another story Mongan is son of Manannan, who had prophesied of this event.  Manannan appeared to the wife of Fiachna when he was fighting the Saxons, and told her that unless she yielded herself to him her husband would be slain.  On hearing this she agreed, and next day the god appeared fighting with Fiachna’s forces and routed the slain.  “So that this Mongan is a son of Manannan mac Lir, though he is called Mongan son of Fiachna."[1199] In a third version Manannan makes the bargain with Fiachna, and in his form sleeps with the woman.  Simultaneously with Mongan’s birth, Fiachna’s attendant had a son who became Mongan’s servant, and a warrior’s wife bears a daughter who became his wife.  Manannan took Mongan to the Land of Promise and kept him there until he was sixteen.[1200] Many magical powers and the faculty of shape-shifting are attributed to Mongan, and in some stories he is brought into connection with the sid.[1201] Probably a myth told how he went to Elysium instead of dying, for he comes from “the Land of Living Heart” to speak with S. Columba, who took him to see heaven.  But he would not satisfy the saints’ curiosity regarding Elysium, and suddenly vanished, probably returning there.[1202]

This twofold account of Mongan’s birth is curious.  Perhaps the idea that he was a rebirth of Fionn may have been suggested by the fact that his father was called Fiachna Finn, while it is probable that some old myth of a son of Manannan’s called Mongan was attached to the personality of the historic Mongan.

About the era of Mongan, King Diarmaid had two wives, one of whom was barren.  S. Finnen gave her holy water to drink, and she brought forth a lamb; then, after a second draught, a trout, and finally, after a third, Aed Slane, who became high king of Ireland in 594.  This is a Christianised version of the story of Conall Cernach’s birth.[1203]

In Welsh mythology the story of Taliesin affords an example of rebirth.  After the transformation combat of the goddess Cerridwen and Gwion, resembling that of the swine-herds, Gwion becomes a grain of wheat, which Cerridwen in the form of a hen swallows, with the result that he is reborn of her as Taliesin.[1204]

Most of these stories no longer exist in their primitive form, and various ideas are found in them—­conception by magical means, divine descent through the amour of a divinity and a mortal, and rebirth.