One example is a Welsh legend of Merlin, who is asked to prophesy a boy's death; he says the boy will fall from a rock. The boy is then dressed in different clothing and brought before Merlin and asked about the manner of his death; Merlin says he will hang. The boy is then disguised as a girl and brought again; Merlin prophesies drowning. Later, while on a hunt, the boy slips from a rock, is caught on a tree and suspended upside-down, with his head in a lake, where he drowns.
Diarmait Mac Cerbaill was a real historical figure, and yet we are told he suffered the threefold death of legends. According to the Life of Columba by Adomnán of Iona, he is told by an Irish seer that his foster-son, Áed Dub ("Black Áed"), will kill him; Diarmait banishes Áed Dub. Then, St. Ruadán prophesies that he would be killed by the roof beam of his hall at Tara; Diarmait has the roof beam removed and thrown into the sea.
With those dangers removed, Diarmait continues his quest to avoid death by asking druids how he will die. They predict a threefold death, "by iron, water, and fire." This would mean slain with a weapon, drowning, and burning. Further, they are him that there will be signs of his impending death: a shirt grown from a flax seed, a woolen mantle made from a single sheep, ale brewed from a single grain of corn, bacon from a sow that has never farrowed.
Diarmait, satisfied that his death by anything other than old age is unlikely, visits the hall of Banbán, where he is shown a shirt, a mantle, and bacon that satisfy the conditions of his imminent death. He decides to immediately leave the hall, but Áed Dub is waiting at the door, stabs him and sets fire to the hall. Prevented from leaving the burning hall, Diarmait climbs into a vat of ale to survive the heat. The burning hall collapses, and the roof beam, which Banbán had found in the sea and used to build his hall, falls and crushes Diarmait.
It is curious to have a prophetic and threefold death attributed to an actual person. The Annals of Tigernach, in the entry for 563, merely states "Diarmaid son of Cearbhall was killed in Ráth Bec in Magh Line by Aodh Dubh son of Suibne Araidhe, king of Ulster, and his head was taken to Cluain and his body was buried in Connere."
Adomnán, for his own reasons, was clearly embellishing. Perhaps his knowledge that Diarmait was dabbling in Christianity was the emphasis, since legend says that Áed Dub suffered a similar threefold death, which Adomnán attributes to divine justice after killing Diarmait. Adomnán would have been drawing from several sources for his Life of St. Columba, including the saga Aided Diarmata ("Death of Diarmait").
One more look at Diarmait, the king who bridged the pagan and Christian eras in Irish kingship, before we move on to something else. This next look will be from the angle of St. Ruadán.
