Thank you for visiting. This article is one installment in a series that explains the “original texts” of the world’s myths and religions — an index page summarizing the original texts of “Celtic mythology.”
Celtic mythology — the hero Cú Chulainn, the Tuatha Dé Danann said to be the origin of the fairies — has greatly influenced fantasy works too. But, as with Greek mythology, no single scripture exists.
In the first place, the ancient Celts did not write their myths down but handed them on orally. Later, medieval Christian monks wrote them down in Irish and Welsh manuscripts, and so they have come down to the present.
This series explains the stories these original texts convey in detail, divided into thematic articles.
You can view the full list, including each myth and religion, from the complete index below.
The Big Picture of Celtic Mythology’s Original Texts
Celtic mythology’s original texts divide broadly into the Irish stories and the Welsh stories, and are gathered, by content, into several “story cycles.”
Listing the major original texts (story cycles) gives the following.
| Original text (cycle) | Region | Content |
|---|---|---|
| Mythological Cycle (Book of Invasions) | Ireland | The battle of the gods, the Tuatha Dé Danann, and the demonic Fomorians |
| Ulster Cycle | Ireland | The deeds of the demigod hero Cú Chulainn. “The Cattle Raid of Cooley” |
| Fenian Cycle | Ireland | The story of the hero Fionn mac Cumhaill and the warrior band Fianna |
| Mabinogion | Wales | A collection of mythic and heroic stories centered on the four “Branches” |
Now, let me introduce what each article explains.
Celtic Myths and LegendsView on Amazon →
European Iconography: Myths, Legends and Fairy TalesView on Amazon →
Article 1: The Age of Gods and the “Book of Invasions”
The first part of the series explains the “Book of Invasions (the Mythological Cycle),” which depicts the rise and fall of the successive peoples who came to Ireland.
It covers in detail the battle of the divine clan skilled in magic and craft, the “Tuatha Dé Danann,” with the native demonic “Fomorians,” and gods such as the light god Lugh, the Dagda, and the war goddess the Morrígan.
Article 2: The Hero Cú Chulainn and the Ulster Cycle
The second part of the series explains the story of Celtic mythology’s greatest hero, “Cú Chulainn.”
It explains richly the “warp-spasm (ríastrad),” in which he transforms into a terrible form in battle; the deadly magic spear Gáe Bolg; the “Cattle Raid of Cooley,” in which he holds off an army all alone; and his tragic end.
Article 3: Fionn mac Cumhaill and the Fianna Knights
The third part of the series explains the story of the hero who leads the warrior band Fianna, “Fionn mac Cumhaill” (the Fenian Cycle).
It covers the tale of the “salmon” that grants wisdom, his son Oisín who crossed to the Land of Eternal Youth, and the tragic love of Diarmuid and Gráinne.
Article 4: The Mabinogion — Welsh Myth and the Source of King Arthur
The fourth part of the series (the finale) explains the Welsh myth collection the Mabinogion.
It covers the stories of the “Four Branches of the Mabinogi” — the fairy woman Rhiannon, the head of the giant Brân that keeps speaking, Blodeuwedd made from flowers — and Culhwch and Olwen, a source of the Arthurian legends.
Celtic Mythology and the Present — the Source of Fairies and Halloween
The appeal of Celtic mythology is that it does not remain a story of the distant past but lives on, transformed, in our present lives and culture.
First, “fairies.” The defeated divine clan the Tuatha Dé Danann is said to have left the earth’s surface and come to dwell under the hills and in the otherworld (Tír na nÓg, the Land of Eternal Youth), which is said to be the source of later fairy tradition. Ireland’s belief in the “sídhe (fairy mounds)” is a remnant of it.
And “Halloween.” It derives from the ancient Celtic harvest festival “Samhain.” On this night, the end of the year, it was believed that the boundary between this world and the next grows thin, and the dead and spirits visit. The custom of dressing up to drive off evil spirits was inherited into the modern Halloween.
The ones who conveyed this Celtic worldview were the priests “Druids,” who bore ritual and knowledge in place of the Celts who had no writing, and the texts that survive today are what medieval monks wrote down of their oral tradition. Many of the images of fairies, Druids, and the otherworld appearing in fantasy literature and games have this Celtic mythology as their source.
To Learn More
Here are some related books. Reading them alongside this series lets you savor this world even more deeply.
Celtic Myth: Goddesses, Heroes and FairiesView on Amazon →
An Illustrated Guide to Celtic MythologyView on Amazon →
Conclusion
In this article, I introduced the big picture of Celtic mythology’s original texts and what the four articles of the series cover. How was it?
Celtic mythology has no single scripture; it is reconstructed from what medieval monks wrote into Irish and Welsh manuscripts of orally transmitted stories.
The battles of the gods, the adventures of the heroes, and the world of fairies — Celtic mythology is a rich treasury of stories that greatly influenced later fantasy literature and the Arthurian legends.
I also explain the original texts of other myths and religions. For the full list, see the complete index of the world’s myths and religions.
For the strength of the gods and heroes, please use this ranking article as a reference too.
I hope you’ll read the next article too.
📚 Series: The Original Texts of Celtic Mythology (1/5)