Newgrange and inbreeding: three ancient myths about the monuments of Brú na Bóinne refer to occurrences of incest

Newgrange and inbreeding: three ancient myths about the monuments of Brú na Bóinne refer to occurrences of incest

In this long-read blog post, Anthony Murphy identifies THREE myths about Newgrange and the Brú na Bóinne monuments which involve episodes of incest. All three of these myths feature kings who – wittingly or unwittingly – carry out acts of incest.

A recent widely-reported DNA study has shed new light on the people who were buried in the Neolithic passage-tombs of Brú na Bóinne and elsewhere in Ireland. Among its findings was the fascinating revelation that an adult male interred in the chamber of Newgrange around 5,200 years ago was the son of an incestuous union. His parents were first-degree relatives – i.e. they were either brother and sister, or father and daughter or mother and son.

Although the authors of the study, which was published in the journal Nature in June, discussed a myth about Dowth which mentions incest, there are at least three ancient stories relating to Newgrange and the great monuments of Brú na Bóinne that refer to inbreeding.

The purpose of this article is to identify these disparate myths and discuss their association with Newgrange, or, in the case of one, Dowth a sister site of Newgrange.[i]

Conjoined spirals

How Dowth got its name

The first is the one mentioned in the Nature article. It is the myth about how and why Dowth was constructed, according to the Dindshenchas, a collection of metrical and prose onomastic material dealing with how eminent places of Ireland got their names.[ii]

Dowth is a sister site of Newgrange, one of three giant passage-mounds in the Bend of the Boyne or Brú na Bóinne complex in County Meath, Ireland, along with Knowth. The tale in the Metrical Dindshenchas about Dowth goes as follows:

Dubad, whence the name? Not hard to say. A king held sway over Erin, Bressal bó-dibad by name. In his time a murrain came upon the kine of Erin, until there were left in it but seven cows and a bull. All the men of Erin were gathered from every quarter to Bressal, to build them a tower after the likeness of the tower of Nimrod, that they might go by it to Heaven. His sister came to him, and told him that she would stay the sun's course in the vault of heaven, so that they might have an endless day to accomplish their task. The maiden went apart to work her magic. Bressal followed her and had union with her: so that place is called Ferta Cuile from the incest that was committed there. Night came upon them then, for the maiden's magic was spoilt. ‘Let us go hence,’ say the men of Erin, ‘for we only pledged ourselves to spend one day a-making this hill, and since darkness has fallen upon our work, and night has come on and the day is done, let each depart to his place.’ ‘Dubad (darkness) shall be the name of this place for ever’, said the maiden. So hence are Dubad and Cnoc Dubada named.[iii]

Clearly, elements of this tale have been sanitised to make them appear more Christian. The reference to the Tower of Nimrod (from the Old Testament book of Genesis – Nimrod was the king of Shinar who was said to have constructed the tower of Babel) is an indication that there was an ingression or infiltration of Christian doctrine into the blatantly pagan mythology, perhaps as an effort to reconcile the two.

Dowth at sunset. The king and his sister committed incest, breaking her magic spell on the sun.


Ronald Hicks, Professor of Anthropology at Ball State University, Muncie, Indiana, agrees that it is clear that at the very least the introduction to the story has been “Christianised”.[iv]

Hicks believes, as I do, that the Dindshenchas story of Dowth is “in all probability a reference to the summer solstice”[v] and points to the fact the nearby Dowth Henge has gaps in its giant banks that are aligned towards the rising sun on summer solstice.

He says the story of the king and his sister “links beautifully to the DNA incest recently discovered and raises many fascinating questions!”

The authors of the new paper, titled A dynastic elite in monumental Neolithic society, led by Dr. Lara Cassidy of Trinity College Dublin, refer to the Dindshenchas tale of Dowth’s alleged origins:

The Brú na Bóinne passage tombs appear in Medieval mythology that relates their construction to magical manipulations of the solar cycle by a tribe of gods, which has led to unresolved speculation about the durability of oral traditions across millennia. Although such longevity seems unlikely, our results strongly resonate with mythology that was first recorded in the eleventh century AD, in which a builder-king restarts the daily solar cycle by copulating with his sister.[vi]

They furthermore state that Fertae Chuile, a Middle Irish placename for Dowth passage-tomb, can be translated as ‘Hill of Sin’ or ‘Hill of Incest’.[vii]

One of the great difficulties with the interpretation of the Dindshenchas passages and verses, apart from the aforementioned quandary of whether these tales have their origins in the dim mists of prehistory or are purely the product of medieval scribes, is that we cannot easily know if the alleged or purported aversion to the “sin” of incest is a purely medieval Christian intervention in the tale, or whether it represents a longer-held disdain or antipathy towards what many cultures would deem a taboo. In this respect, the Dindshenchas story of Dowth provides little by way of answers. Similarly, the two versions of the Dowth story (there is another included with the Dindshenchas poem about Knowth) offer no conclusive answer to the question of whether the builders of the megalithic monuments were forced or coerced into building the structures or whether they gladly participated in the spirit of community fellowship or zeal.[viii]

Conjoined spirals

The birth of Cúchulainn

Another myth about Newgrange which features a reference or allusion to incest is found in the Ulster Cycle of tales and relates to the birth of Cúchulainn, the great warrior of the saga Táin Bó Cúailnge, ‘The Cattle Raid of Cooley’. There are at least three different versions of this tale,[ix] and the one summarised here is from the earliest source, the now-lost Lebor Dromma Snechta, the Book of Droim Sneachta, compiled in the seventh and eighth centuries.[x]

The most familiar version of the story features the Tuatha Dé Danann deity Lugh as the supernatural father of the boy Sétanta (the name by which Cúchulainn was known in his youth). These stories place the conception of the wonder-boy at Bruig na Bóinde (Newgrange), the palace or otherworld mansion of the gods, which may be an effort on behalf of the storytellers to accentuate Sétanta’s divine origin.[xi]

Conchobar and the Ulster chiefs were at Emain Macha (mythical capital of Ulster) when a flock of birds (likely to have been swans) came along and ate all the grass and vegetation. The Ulstermen became angry at the destruction and chased the birds away in their chariots. Among the chasing group were Conchobar and his sister Deichtine (some variants of the story say she was his daughter). The birds flew south across the Fews Mountains and on towards Breg plain. As nightfall approached, three birds separated from the flock and led the pursuers to Brug na Bóinne (Newgrange).[xii]

Night came upon them at Newgrange.

Night came and it snowed heavily. The horses were unyoked from the chariots and Conchobar ordered the people to seek shelter. They found a solitary house and the whole troop was welcomed inside. The man of the house told them his wife was in labour, and Deichtine went to help, and soon a son was born. In the morning, the group returned to Emain Macha, and brought the infant with them. He was nursed until he was a young boy, but fell ill and died, which greatly saddened his foster-mother Deichtine. Deichtine requested a drink from a copper vessel and “every time she put the vessel to her mouth, a tiny creature would leap from the liquid towards her lips”.[xiii] The tiny creature slipped into her mouth with the water.

There follows an episode that falls into the category of ‘miraculous births’, or ‘virgin births’, found in many mythologies around the world.[xiv] That night, she dreamed that a man came to her and told her that he had brought her to Brug na Bóinne to sleep with her there, and that it was in fact his house that she had entered.[xv] He said that “the boy she had reared was his, that he was again planted in her womb and was to be called Sétanta, that he himself was Lug mac Ethnenn.”[xvi]

Thereafter, Deichtine indeed became pregnant. The Ulaid (Ulstermen) were troubled since they did not know the father, and they surmised that Conchubur had fathered the child while drunk, for Deichtine used to sleep next to him. Conchubur then betrothed his daughter to Súaltaim son of Roech. Deichtine was greatly embarrassed at having to go to Súaltaim’s bed while being pregnant, so, when the time came, she lay down in the bed and crushed the child within her. Then she went to Súaltaim, and at once she became pregnant by him and bore him a son.[xvii]

Celtic myth scholar James MacKillop says that in the third (and perhaps least familiar) version of the story of the birth of Cúchulainn, “Conchobar, as either Deichtine’s father or brother, commits incest with her to father Cúchulainn”.[xviii]

Conjoined spirals

The king sleeps with his daughter

The third story that connects Newgrange and incest is one of the best-known myths concerning the great monument of Bruig na Bóinde (Newgrange), Tochmarc Étaíne, The Wooing or Courting of Étaín. The tale was known only in fragmented form in the 12th century Lebor na hUidre (The Book of the Dun Cow) until the 20th century, when another, complete version of the story was discovered among the vellum leaves of the Yellow Book of Lecan in Cheltenham in the 1930s.[xix]

It is a remarkable story not least because it deals with the notion of metempsychosis or reincarnation. The central figure of the myth, Étaín Echraide (the epithet Echraide relates to horses or steeds and probably means ‘horse-rider’[xx]) is described as the most beautiful woman in Ireland. Tochmarc Étaíne chronicles three disjointed yet related episodes,[xxi] each recalling a different lifetime or iteration of Étaín. Each portion of the tale has love rivalry as a theme – and it is not always Étaín who is the object of the rivalry. The unifying character among the dramatis personae is Midir, who in all three episodes is a suitor or courter or lover of the beautiful Étaín.

It is necessary here to attempt to summarise the three segments or episodes in order to (a) establish how the story relates to Newgrange; (b) to briefly show that Midir is essentially the one who ‘woos’ Étaín in all three episodes and (c) to recount the circumstance of the incestuous act and how it relates to the overall tale.

Episode 1

Dagda, chief of the deities, sleeps with Bóinn, wife of Elcmar, at Brug na Bóinne (Newgrange) after sending Elcmar away under a magic spell. The child Oengus Óg is conceived. To hide the adultery, Oengus is secreted away to be fostered by Midir of Brí Léith (near Ardagh, County Longford). Later, when Oengus has grown up and taken possession of Brug na Bóinne by forcing Elcmar out through verbal ambiguity (with the aid of his father, the Dagda), Midir comes to visit him at the Brug. While intervening in a row between two groups of boys playing sports, Midir’s eye is knocked out. He demands compensation from Oengus in the form of the most beautiful woman in Ireland, Étaín, daughter of Ailill.[xxii] Oengus wins her for Midir, but only after completing several Herculean tasks at the instruction of Ailill.[xxiii]

Midir sleeps with Étaín at the Brug and they stay there for a year before he returns home with her to Brí Léith, but his first wife, Fuamnach, is (perhaps understandably!) jealous of her husband’s new concubine. Fuamnach strikes Étaín with a wand of rowan and turns her into a pool of water. The pool transforms into a worm and then a purple fly which is miraculous by nature of its size and sweet fragrance. Midir knows the fly is really Étaín and they stay together. However, Fuamnach knows the fly’s identity and causes a wind that drives her out onto the rocks at sea. Étaín endures this misery for seven years until eventually she lands on Oengus’ garment on the Brug (Newgrange). Oengus protects Étaín for a while, carrying her in a sunny crystal bower but when Fuamnach finds out the identity of the fly, she causes Étaín to be blown away again. She alights on a rooftop in Ulster and falls into the drinking cup of a woman, the wife of Étar, an Ulster king. The woman swallows the fly and Étaín is reborn as the daughter of Étar. Some 1,012 years have elapsed since Étaín was born as daughter of Ailill.

Episode 2

Another thousand years have elapsed when the second part of the tale begins. The high king of Ireland, Eochaid Airem, seeks the most beautiful woman in Ireland to be his wife. She is identified as Étaín daughter of Étar, and Eochaid Airem marries her. However, the king’s brother, Ailill, is so enamoured by her beauty that he falls sick with love for her. His shame prevents him from discussing his illness, so no one can cure him. Eochaid leaves to go on a royal circuit of Ireland, and in his absence Ailill finally confesses to Étaín his deep love for her. Étaín agrees to sleep with him to cure him of his sickness, but not in the king’s residence. She arranges a tryst on a nearby hilltop. Ailill stays awake all night but as the appointed hour arrives he falls asleep. An imposter in Ailill’s likeness comes to Étaín and they sleep together. This occurs for three consecutive nights until Étaín realises it is not Ailill. ‘It is not you I am to meet,’ she says, and the imposter reveals his identity. He is Midir of Brí Léith, her husband from her previous life. He pleads with her to elope with him, but she refuses to do so without the consent of her husband, Eochaid Airem. She returns home, as does her husband, and Eochaid rejoices that his brother Ailill has been cured, and Étaín’s honour has not been sullied by sleeping with her husband’s brother.

Episode 3

Midir’s unquenched longing for Étaín leads him to engage in trickery against her husband, king Eochaid Airem. On a summer day, a warrior arrives at Tara (the seat of the high king) and challenges Eochaid to a game of fidchell (an old Irish board game similar to chess). He identifies himself as Midir of Brí Léith. In three consecutive games Eochaid wins, extracting extravagant prizes from Midir, which include fifty horses, fifty boars, fifty gold-hilted swords, the clearing of stones from the plain of Mide and the construction of a causeway across the bog of Móin Lámrige. In the fourth game, they agree that the winner should name the stakes. When Midir wins, he asks if he can put his arms around the king’s wife, Étaín, and give her a kiss. After some deliberation, Eochaid agrees, but tells Midir to come back in a month’s time for the promised kiss.

Midir challenged king Eochaid Airem to a game of fidchell (chess) at Tara.

When the appointed day arrives, Eochaid has Tara surrounded with armies and warriors and secures the doors and gates. However, Midir, looking more handsome than ever, magically appears in the midst of the royal house. Eochaid reminds him of the extent of their agreement and bids him to embrace and kiss Étaín. With his weapons in his left arm, he puts his right arm around Étaín and carries her up through the skylight or smoke-hole of the house and flies away. The warriors of Tara report seeing two swans flying away from Tara in the direction of Síd ar Femuin.

Eochaid and his entourage resolve to regain Étaín, even if that results in the destruction of every sídh in Ireland. They dig Síd ar Femuin but there is no sign of Midir and Étaín. They go north to Brí Léith, Midir’s residence, and dig there, but every night the part that they dug up during the day is restored. Midir eventually emerges and produces fifty women, all of whom look like Étaín, so that nobody can tell who the real Étaín is. The king claims that he will know Étaín by the way she pours a drink, and insists that all fifty of the women pour a drink so that he can pick his wife out. He chooses who he assumes to be his wife based on this test, and returns to Tara with her to resume married life.

However, the woman with whom he resides is not Étaín. Midir returns to Tara and, having obligated the king to desist from further recrimination against him, reveals that Étaín was pregnant when he had taken her through the skylight of Tara. She had given birth to a daughter, and it was in fact that daughter whom Eochaid had chosen from the fifty drink-pouring women. In other words, the king had been sleeping with his own daughter.

“Your wife was pregnant when I took her from you,” Midir tells Eochaid Airem. “She bore you a daughter, and it is that daughter who is with you now. Your wife is with me, and you have let her go a second time.” With these words, Midir departs.[xxiv]

Eochaid is understandably distressed that his wife was gone and that he had slept with his own daughter. Furthermore, his daughter became pregnant and bore a daughter. “O gods,” he said, “never will I look upon the daughter of my daughter.”

The child of the king’s incestuous union is put out to die, but she is found by Findlám, a herdsman, and his wife, who raise her. Neither the daughter of Étaín who Eochaid had chosen from among the fifty drink-pourers, nor indeed the daughter of their incestuous union, is named in the tale.

Conjoined spirals

One more story

There is one further story about incest in Irish myth which is not directly related to the Brú na Bóinne monuments but has aspects which perhaps connect it with Tochmarc Étaíne. It relates to Clothru, a sister of Medb and daughter of Eochaid Feidlech, a king of Tara. (This king is often confused with Eochaid Airem of Tochmarc Étaíne[xxv]).

Clothru has sexual intercourse with her three brothers Bres, Nár and Lothar (collectively known as the Three Finns of Emain[xxvi]) preceding the battle of Druim Criaich, which results in the conception of Lugaid of the red stripes, an Ulster Cycle king.[xxvii]

Later, Lugaid and his mother Clothru engage in a second act of incest to produce Crimthann Nia Náir.[xxviii] Before she had engaged in either act of inbreeding, Clothru had visited the otherworld and eaten divine food.[xxix]

NG10 and a ‘dynasic elite’ of Newgrange

The authors of the Nature paper sampled 44 genomes, 42 of them from Neolithic sites in Ireland (including the sample ‘NG10’, a portion of the skull of an adult male retrieved from the chamber of Newgrange during excavation of the monument in the 1960s by Prof. Michael J. O’Kelly) and two from the earlier Mesolithic period. The Newgrange male was labelled NG10 in the study.

Co-operative ideology is often proposed as a motivating factor in the construction of megalithic monuments, but the magnitude of human labour needed to erect giant structures such as Newgrange has led some scholars to assert that a hierarchy was required.

The most extreme case of this, according to the paper’s authors, “is a small elite marshalling the labour of the masses.”[xxx] They continue:

Here we present evidence that a social stratum of this type was established during the Neolithic period in Ireland. We sampled 44 whole genomes, among which we identify the adult son of a first-degree incestuous union from remains that were discovered within the most elaborate recess of the Newgrange passage tomb.[xxxi]

Socially endorsed inbreeding of this nature is very rare, they say, and occur “almost exclusively among politico-religious elites – specifically within polygynous and patrilineal royal families that are headed by god-kings”.[xxxii]

Conjoined spirals


I have identified four stories from Irish mythology written down in medieval times relating to incest or inbreeding. The supposed longevity of these tales is hotly contested by modern scholars, and yet aspects of some of the ancient tales have been confirmed by modern archaeology and genetic studies.[xxxiii] Three of the four myths discussed have their setting, at least in part, at the great monuments of Brú na Bóinne. In these three, summarised above, there is guilt or regret associated with the act of incest.

Eochaid Airem is distressed when he realises he has slept with his own daughter, and is so ashamed of the daughter of that union that he abandons her and she is left out to die. Deichtine is greatly embarrassed at having to go to Súaltaim’s bed while pregnant, and crushes the child inside her.

In the Dowth story from the Dindshenchas, if Fertae Chuile means ‘hill of sin’, that might indicate remorse or shame around what had happened. But a complicating factor in all three stories is the fact that they were all written down by ecclesiastical scribes, for whom the idea of incestuous union would undoubtedly have been unthinkable. Did they thus alter the stories to better appeal to the sensitivities of their own Christian beliefs? We may never be able to answer that question. 

[i] The other is, of course, Knowth.

[ii] Dindshenchas is a combination of Irish words – Dind, meaning a ‘noteworthy place’, and senchasa, meaning ‘old stories’, ‘ancient history’ or ‘tradition’.

[iii] Gwynn, Edward (1924), The Metrical Dindshenchas Part IV, Royal Irish Academy Todd Lecture Series Volume XI, pp. 271-3.

[iv] Ronald Hicks, personal communication, June 2020.

[v] Ibid.

[vi] Cassidy, Lara M., et al, (2020), A dynastic elite in monumental Neolithic society, Nature, Vol 582, (published online at, p. 386.

[vii] Ibid., p. 386. See also Carey, John, Time, memory and the Boyne necropolis, Proceedings of the Harvard Celtic Colloquium, Vol. 10, pp. 24-36. The word from which cuile is derived would seem to be col or colach. See and (retrieved 5th July 2020).

[viii] This question is addressed more comprehensively, although not conclusively resolved, in Murphy, Anthony (2017), Mythical Ireland: New Light on the Ancient Past, chapter 4.1: ‘Neolithic passage-tomb construction: Cooperation or enforced labour?’, pp. 127-137.

[ix] MacKillop, James (1998), Dictionary of Celtic Mythology, Oxford University Press, p. 117.

[x] Stout, Matthew (2017), Early Medieval Ireland: 431-1169AD, Wordwell, p. 116.

[xi] Gantz, Jeffrey (1988), Early Irish Myths and Sagas, Penguin Books, p. 131.

[xii] The tale of How Cúchulainn was Begotten can be found in Kinsella, Thomas (2002)[1969], The Táin: Translated from the Irish Epic Táin Bó Cúailnge, Oxford University Press.

[xiii] Gantz, op. cit., pp. 132-3.

[xiv] Ellwood, Robert S. & Alles, Gregory D. (2007), The encyclopedia of world religions (revised edition), Facts on File Inc., p. 467.

[xv] Ibid., p. 133.

[xvi] Kinsella, op. cit., p. 23. Lug mac Ethnenn is also known as Lug Samildánach (Lugh the Many-Gifted) and Lug Lamfada (Lugh of the Long Arm).

[xvii] Gantz, op. cit., p. 133.

[xviii] MacKillop, op. cit., p. 117.

[xix] Gantz, op. cit., p. 37.

[xx] MacKillop, op. cit., p. 172. See eDIL s.v. echrad, echraid (, retrieved 4th July 2020.

[xxi] Dillon, Myles (1959), ‘Tochmarc Étaíne’, in Irish Sagas, p. 17, says “it is one story in three, as it were, a comedy in three acts”.

[xxii] The demanded restitution includes ‘A chariot worth seven cumals and clothing appropriate to my rank and the fairest woman in Ériu’. (Gantz, p. 43.)

[xxiii] The tasks are the clearance of twelve plains, the diverting of twelve rivers to drain the land, and Étaín’s weight in gold and silver.

[xxiv] Gantz., op. cit., p. 59.

[xxv] MacKillop, op. cit., p. 164.

[xxvi] Ibid., p. 274.

[xxvii] Ingridsdotter, Kicki (2013), Motivation for incest: Clothru and the battle of Druim Criaich, Studia Celtica Fennica 10, pp. 45–63.

[xxviii] MacKillop, op. cit., p. 82.

[xxix] Ibid., p. 99.

[xxx] Cassidy et al, op. cit., abstract.

[xxxi] Ibid.

[xxxii] Ibid.

[xxxiii] For further discussion of how myth and folklore foreshadowed discoveries by 20th century scientists, see Murphy (2017), op. cit., chapters 1.3,1.4 and 1.5.

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In this reissued edition of their best-selling book, Anthony Murphy and Richard Moore present evidence suggesting the builders of monuments such as Newgrange and its Boyne Valley counterparts were adept astronomers, skilled engineers and capable surveyors. Their huge monuments are memorials in stone and earth, commemorating their creators’ perceived unity with the cosmos and enshrining a belief system which resulted from a synthesis of science and spirituality.

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