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 name. (Gwynn 1924, 271).
Dowth is an anglicization of the Irish Dubad, just as Knowth derives from Cnogba. The name Newgrange, however, owes nothing to the native language. In the fourteenth century the surrounding land became one of the outlying farms or granges of the monastery of Mellifont and in due course the monument took the name of the locality, New Grange, rather than its traditional one of An Brug (the bru or mansion) by which it is known in the early literature (C. O'Kelly 1978, 74-6).
The oldest traditions associate the Boyne monuments with the spirits of the Other world, the Tuatha De Danann (people of the goddess Danu), a god-like race who were said to have inhabited Ireland before the coming of the Gael or Celts. Their god-king was the Dagda and he was said to have built the mound of Newgrange, the Bru for himself and his three sons. He stole Boann (the River Boyne) from her rightful husband, Elcmar, and married her himself. Elcmar's shepherd was named Boadan and Dubad or Dowth was said to be the grave of Boadan (Fert Boadain).
Another reference to Dowth is found in the great compendium of place-lore known as the Dindshenchas which seeks to explain in prose and verse how various well-known places got their names. This tale is not as familiar as those relating to the Bru and other famous sites and in the absence of more specific information about how and why the mound of Dowth was built, let us substitute the above account from the Dindshenchas in the Book of Leinster, a compilation of about AD 1160.
Dowth is mentioned several times in the annals. The Annals of Ulster, 862 recorded that:
The great mound features in the Ulster Cycle myth, where Cuchulainn, on the day he recieves his weapons and chariot, comes to Dowth and fights a giant, the first of three brothers at a ford over the river, and brought their three heads back to Ulster as trophies. Cuchulainn, son of Lugh, was concieved at Newgrange close by; perhaps the story represents him bringing the wisdom of the three mounds back with him in the three heads.
The Irish name for Dowth is Dubad, which means 'Darkness'. In the mythology of the Boyne Valley, Dowth was the Brú of the Druid Bresal, who was attempting to build a great tower which could reach up to the heavens. Bresal employed all the men of Ireland to build the tower in a single day, and to this end his sister cast an enchantment that the sun will not set until the tower was complete, a reference to the solstice sun setting in the south chamber.
However, her brother was overcome with lust and commited incest with her, breaking the enchantment and causing the sun to set before the tower is built. 'Night has come upon us', lamented his sister, 'and Dubad shall be the name of this place forever'. This mythological origin of the name fits the cairn as both the internal passages are oriented to sunsets, one to Samhain when the sun 'dies' for the year as it goes underground, the other to the longest night of the year, the winter solstice sunset.