Vita Columbae
There are a number of stories in Celtic mythology that clearly are formed by they Tripartate functions of Proto-Indo-European. The theme of triple-death occurs in several places in medieval Celtic sources. The first story comes from the Life of St. Columba (Vita Columbae):
Aedh, surnamed the Black, descended of a royal family, and a Cruthinian by race. Aedh wore the clerical habit, and came with the purpose of residing with him in the monastery for some years. Now this Aedh the Black had been a very bloodthirsty man, and cruelly murdered many persons, amongst others Diarmuid, son of Cerbul, by divine appointment king of all. This same Aedh, then, after spending some time in his retirement, was irregularly ordained priest by a bishop invited for the purpose... The bishop, however, would not venture to lay a hand upon his head unless Findchan, who was greatly attached to Aedh in a carnal way, should first place his right hand on his head as a mark of approval. When such an ordination afterwards became known to the saint, he was deeply grieved, and in consequence forthwith pronounced this fearful sentence on the ill-fated Findchan and Aedh... And Aedh, thus irregularly ordained, shall return as a dog to his vomit, and be again a bloody murderer, until at length, pierced in the neck with a spear, he shall fall from a tree into the water and be drowned... But Aedh the Black, a priest only in name, betaking himself again to his former evil doings, and being treacherously wounded with a spear, fell from the prow of a boat into a lake and was drowned.
This story of triple-death corresponds to the elements which Evans finds in a whole host of similar stories. In all of these stories, the tripartate death is foretold. Here St. Columba foretells the triple death of Aedh. At the same time Columba's prophecy is a curse or a punishment which he dispenses to Aedh because of his sins. This leads to the next element common in many 'Triple-death' stories, the sins of the warrior. According to Dumezil, the warrior often commits a sin against each one of the functions. He is punished for each sin, with a punishment fitting for his crime. In this passage from the Life of St. Columba, three specific sins are mentioned. Aedh blasphemes by being ordained a priest outside of the Church. This is a sin against the priestly function of Indo-European society. Aedh's second sin is murder; he has killed numerous people, most notably King Diarmuid. This is a sin against the warrior function. Aedh's last sin is against the productive/fertile function in Indo-European society, he has slept with another man—an act which is by its very nature unfertile.
The Tripartite death of Aedh is linked with another story of triple-death. Diarmuid, who is killed by Aedh, also dies a triple death:
When the king sent men to arrest Aedh, St. Ronan hid him and so Diarmuid had Ronan arrested and tried in his stead. He was condemned by the ecclasiastics for this act and Ronan himself uttered the famous curse, 'Desolate be Tara forever!' Soon after, Tara was abandoned, never to achieve its former splendor... had an affair with Flann, so Diarmuid had Flann's fortress burnt over his head. Sorely wounded, Flann tried to escape the flames by crawling into a vat of water where he drowned... Bec Mac De prophesied that Diarmuid would be killed by Flann's kinsman, Aedh Dubh in the house of Banban... The manner of his death would be by slaughter, by burning, by drowning and by the ridge pole of a roof falling on his head... The Prophecy seemed so unlikely that Diarmuid scorned it, even when Banban invited him to a feast... Aedh Dubh was there and stabbed the High King with his spear. Wounded, Diarmuid fled back into the house. Aedh Dubh's men set fire to it. Seeking to escape the flame, Diarmuid scrambled into a vat of ale. A burning ridge pole fell on to his head. The prophecy was fulfilled (Ellis, 84).
Both of the elements which Evans discusses are present in this story of Diarmuid's death. In this story, there is a prophecy of the threefold death before it occurs. In fact, Diarmuid's death is foretold by three different men in the original story. Diarmuid has also clearly violated two of the three functions. He sins against the sanctity of the priestly function, by trying St. Ronan. For this crime Ronan curses the throne at Tara. Diarmuid also murders Flann, a violation of the warrior function. Diarmuid is punished for his transgressions by the triple nature of his death.
Read more about this topic: Threefold Death