Although the majority of Irish and Scottish Mediaeval manuscripts containing the literature we now describe as Irish and Scottish mythology have been lost or destroyed a significant body of materials have survived (for instance the very important Cion Droma Sneachta “Booklet of Droim Sneachta” is lost to us). The three most important sources to have come down to us are the late 11th or early 12th century Leabhar na hÚidhre (or “Book of the Dun Cow”), the early 12th century Leabhar na Nuachongbhála (also known as the Leabhar Laighean or “Book of Leinster”), and the so-called Rawlinson Manuscript B 502 which may be or contain part of the lost 12th century Leabhar Gleanna Dá Loch (“Book of Glendalough”).

Despite the relatively late periods given to these manuscripts most of the materials they contain predates their composition and a few can be dated back as far as the 5th or 6th centuries on linguistic grounds. Other crucial documents include a group of five manuscripts dating to the late 14th or early 15th centuries: the Leabhar Buidhe Lecain (“Yellow Book of Lecan”), the Leabhar Mór Leacain (“Great Book of Lecan”), the Leabhar Uí Mhaine (“Book of the Uí Mhaine”), the Leabhar Bhaile an Mhóta (“Book of Ballymote”) and the Leabhar Fhear Maí (“Book of Fermoy). Much later 17th century works such as Seathrún Céitinn’s Foras Feasa ar Éirinn (“Foundation of Knowledge on Ireland”) and the collaborative Annála na gCeithre Máistrí (“Annals of the Four Masters”) are also important, particularly as these later compilers and writers may have had access to manuscript sources that have since been lost or forgotten.

When using these materials it is always necessary to question the impact of the circumstances in which they were produced. The vast majority of the manuscripts were created by scribes and monks who may well have been torn between the desire to record the pre-Christian traditions of Ireland and Scotland on the one hand and their religious hostility to those self-same non-Christian traditions of their ancestors on the other. As a result most of the later manuscript sources formed part of a literary movement to create a history for Christian Ireland that could bear comparison with that of other Christianised peoples in Europe (for instance the works of Nennius, Geoffrey of Monmouth and the British monastic schools). This movement, taking root in the monasteries of Medieval Ireland, slowly built a new body of historical and genealogical works, and legends, for a newly Christianised people based upon indigenous pre-Christian oral beliefs mixed with Biblical, ecclesiastical and Classical influences from across Europe and beyond.

The Cycles

Traditionally Irish scribes divided their literary corpus into two basic schemes, primary tales and secondary tales, almost certainly continuing native practice. These were then further divided into sub-classes based upon themed genres: cattle-raids, plundering, battles, wooings, voyages, adventures, etc. However, from the 19th century onwards scholars have tended to divide what we call Irish and Scottish Mythology into four distinct, if overlapping, legendary or literary cycles. These are: the Seanchas (the Mythological Cycle; though Seanchas is also the name for the mythological tradition as a whole), the Rúaríocht (the Ulster or Red Branch Cycle), the Fiannaíocht (the Fenian or Ossianic Cycle) and the Scéalta na Rí (the Historical or Kings’ Cycle). Additionally there are also a number of extant early texts as well as a large number of recorded folk tales that do not fit into any of these neat categories, though they often feature characters, places or events from one or more of the four great cycles.

Seanchas

The Seanchas is the least well preserved of the four categories. The most important sources for it are the Dinnseanchas or “Lore of (Prominent) Places” and the Leabhar Gabhala Éireann ”Book of the Takings of Ireland” (commonly known as the Book of Conquests or Invasions). Other manuscripts help fill out the cycle with important tales such as the Aisling Aonghais “Dream of Aonghas”, the Tochmharc Éadaoine “Wooing of Éadaoin” and independent accounts of the first and second battles of Má Tuireadh. Additionally, the body of stories with the genre titles of the Eachtraí “Adventures” and the Iomramhaí “Voyages” have become very rich sources of mythic lore. The Eachtraí essentially recount tales of visits to the Irish Otherworld, usually by a hero or heroes, and would seem as a storytelling style to be of very ancient origin. In fact they almost certainly continue a pre-Christian tradition of narrative, albeit much adapted by the monastic scribes. The most famous (if historically late) legend is Oisín in Tír na nÓg “Oisín in the Land of the Young” and belongs to the Fiannaíocht, but several free-standing adventures survive including the Eachtra Choinla “Adventure of Conla”, the Eachtra Laoire “Adventure of Laoire”, and the very important Eachtra Bhrain mac Feabhail “Adventure of Bran son of Feabhal” all of which are of very early dates.

The Iomramhaí on the other hand are tales of sea journeys to the Otherworld (whether explicitly or in disguise). These probably grew from the influence of Classical literature in the Christian period combined with the same Otherworld elements that inform the Eachtraí. Of the many iomramhaí mentioned in the manuscripts, only three survive: the Iomramh Mhaoil Dúin “ Voyage of Maol Dúin”, the Iomramh Uí Chorra “Voyage of the Uí Chorra”, and the Iomramh Sneadhghais agus Mac Riaghla “Voyage of Sneadhghas and Mac Riaghla”. The Voyage of Maol Dúin is the forerunner of the later Voyage of Naomh Breannán. It should also be noted that the Otherworldly adventures of Bran son of Feabhal are sometimes known as the Iomramh Bhrain mac Feabhail.

The Dinnsheanchas

The Dinnsheanchas is the great topographical compendium of early Ireland, explaining the names and stories of significant places throughout the island in a sequence of poems. It is probably the major surviving source of Irish bardic verse with nearly 200 poems containing lots of important information on figures and stories from the Mythological Cycle. The poems are accompanied by an incomplete prose commentary, now known as the Prose Dinnsheanchas which contains much valuable information (while the main poetical body is usually known as the Metrical Dinnsheanchas).

Leabhar Gabhála Éireann

The Leabhar Gabhála Éireann itself is a synthetic-history of Ireland (and Scotland) started in the monastic schools in the 6th and 7th centuries and reaching its most developed form in the 12th century. It subsumed the pre-Christian oral beliefs of the Irish and Scottish peoples into the body of the Roman, Greek and Judaeo-Christian myths and histories created or accepted by the early Christian Church in Europe to give the Irish and Scots a suitable Church-approved framework in which much of their annals, genealogies, poetry and literature could be placed. As a result the pagan myths and lore of the pre-Christian Irish and Scots pervade the framework, albeit largely in a hidden or debased form.

The Ceasaraigh

Under this literary schema the ancestry of the Irish was of course traced back to the Biblical Ádhamh “Adam”. Through his line came the first of several groups of settlers on the island of Ireland. These are the Ceasaraigh or the followers of Ceasair, daughter of Bioth son of Naoi (“Noah”) and his wife Biorean, which comprised of fifty women and three men (Bioth, Fionntán and Ladhra, who divided the women between them). They lived in Ireland for a period of time (varying in the accounts) before the Biblical deluge took them all except for one survivor (the fantastical, shape-changing figure of the immortal Fionntán son of Bóchra or Bóchna “Ocean”).

The Parthalánaigh

The Ceasaraigh were followed after the receding of the flood waters by the Parthalánaigh ”People of Parthalán”, under their leader Parthalán son of Seara, another descendant of Naoi (Parthalán is derived from the Latin “Bartholomaeus” which featured in several early and influential continental Christian histories). These settlers defeated another, unrelated invader, the monstrous Fomhóraigh, led by one Ciochal Grigenchosach son of Goll, but they were later wiped out by a deadly plague.

The Clann Neimheidh

The third settlement in Ireland, by the Clann Neimheidh ”Family of Neimheadh”, lasted for many years. Neimheadh (“Sacred One”), a son of Aghnamhan, is another descendant of Naoi and distantly related to Parthalán. He led his people in four great victories over the Fomhóraigh, the most important against their leaders Gann and Seanghann. After his death in a plague with 3000 of his followers, the Clann Neimheidh lived under the oppression of the Fomhóraigh Morc and Conann, paying a heavy tribute of two thirds of their children, wheat and milk each year at Samhain, until they rose in insurrection against their overlords. They attacked Túr Chonainn, the island stronghold of the Fomhóraigh, in a victory that turned pyrrhic as a tidal wave overwhelmed them. Only one boat load of 30 men escaped this catastrophe. Some fled southward to An Ghréig (Greece), while others went into the misty north of the world. It is from these two groups of exiles that the next two waves of settlers descended. 

The Fir Bholg

Those who went to An Ghréig became the ancestors of a people known as the Fir Bholg ”Men (People) of Bolg” (a race which in fact also contained two other sub-groups known as the Gailíon and the Fir Dhomhnann “Men of Domhnainn”). Their descendants served in slavery for many years until eventually they rose up and migrated back to Ireland under their leader Eochaidh son of Earc. 

The Tuatha Dé Danann

Those who went northward became the Tuatha Dé Danann ”Peoples of the Goddess Dana”. Not much is known of Tuatha Dé prior to their invasion of Ireland, other than that they came from four magical cities in the northern islands of the world where they acquired their knowledge and magical attributes. These four cities also contained four great talismans which they brought with them. From Fálias came the Lia Fáil “Stone of Fál” on which their kings were proclaimed. From Gorias came the Claíomh Solais “Sword of Light” wielded by Nuadha. From Muirias came the cauldron of the Daghdha, and from Fionnias came the Sleá Lúgh or “Spear of Lúgh”.

The Clann Mhíle

Altanna (Articles):

1. Tuatha Dé Danann by Séamas Ó Sionnaigh
2. Na Fomhóraigh by Séamas Ó Sionnaigh
3. Lucharacháin by Séamas Ó Sionnaigh
4. An Sí by Séamas Ó Sionnaigh
5. Na Fathaigh by Séamas Ó Sionnaigh
6. Na Bocánaigh, Na Bánánaigh by Séamas Ó Sionnaigh
7. Na Púcaí by Séamas Ó Sionnaigh
8. Na Péisteanna by Séamas Ó Sionnaigh
9. Na Murúcha by Séamas Ó Sionnaigh
10. Seanchas Agus Litríocht na nGael by Séamas Ó Sionnaigh
11. Na Fianna by Séamas Ó Sionnaigh
12. An Gal Gréine by Séamas Ó Sionnaigh

Online Sources For The Above Articles:

1. Warriors, Words, and Wood: Oral and Literary Wisdom in the Exploits of Irish Mythological Warriors by Phillip A. Bernhardt-House
2. Irish Perceptions of the Cosmos by Liam Mac Mathúna
3. Water Imagery in Early Irish by Kay Muhr
4. The Bluest-Greyest-Greenest Eye: Colours of Martyrdom and Colours of Winds as Iconographic Landscape by Alfred K. Siewers
5. Fate in Early Irish Texts by Jacqueline Borsje
6. Druids, Deer and “Words of Power”: Coming to Terms with Evil in Medieval Ireland by Jacqueline Borsje
7. Geis, Prophecy, Omen and Oath by T. M. Charles-Edwards
8. Geis, a literary motif in early Irish literature by Qiu Fangzhe
9. Honour-bound: The Social Context of Early Irish Heroic Geis by Philip O’Leary
10. Space and Time in Irish Folk Rituals and Tradition by Lijing Peng and Qiu Fangzhe
11. The Use of Prophecy in the Irish Tales of the Heroic Cycle by Caroline Francis Richardson
12. Early Irish Taboos as Traditional Communication: A Cognitive Approach by Tom Sjöblom
13. Monotheistic to a Certain Extent: The ‘Good Neighbours’ of God in Ireland by Jacqueline Borsje
14. The ‘Terror of the Night’ and the Morrígain: Shifting Faces of the Supernatural by Jacqueline Borsje
15. Brigid: Goddess, Saint, ‘Holy Woman’, and Bone of Contention by C.M. Cusack
16. War-goddesses, furies and scald crows: The use of the word badb in early Irish literature by Kim Heijda
17. The Enchanted Islands: A Comparison of Mythological Traditions from Ireland and Iceland by Katarzyna Herd
18. The Early Irish Fairies and Fairyland by Norreys Jephson O’ Conor
19. The Washer at the Ford by Gertrude Schoepperle
20. Milk Symbolism in the ‘Bethu Brigte’ by Thomas Torma
21. Conn Cétchathach and the Image of Ideal Kingship in Early Medieval Ireland by Grigory Bondarenko
22. King in Exile in Airne Fíngein (Fíngen’s Vigil): Power and Pursuit in Early Irish Literature by Grigory Bondarenko
23. Sacral Elements of Irish Kingship by Daniel Bray
24. Kingship in Early Ireland by Charles Doherty
25. The King as Judge in Early Ireland by Marilyn Gerriets
26. The Saintly Madman: A Study of the Scholarly Reception History of Buile Suibhne by Alexandra Bergholm
27. Fled Bricrenn and Tales of Terror by Jacqueline Borsje
28. Supernatural Threats to Kings: Exploration of a Motif in the Ulster Cycle and in Other Medieval Irish Tales by Jacqueline Borsje
29. Human Sacrifice in Medieval Irish Literature by Jacqueline Borsje
30. Demonising the Enemy: A study of Congall Cáech by Jacqueline Borsje
31. The Evil Eye’ in early Irish literature by Jacqueline Borsje and Fergus Kelly
32. The Irish National Origin-Legend: Synthetic Pseudohistory by John Carey
33. “Transmutations of Immortality in ‘The Lament of the Old Woman of Beare’” by John Carney
34. Approaches to Religion and Mythology in Celtic Studies by Clodagh Downey
35. ‘A Fenian Pastime’?: early Irish board games and their identification with chess by Timothy Harding
36. Orality in Medieval Irish Narrative: An Overview by Joseph Falaky Nagy
37. Oral Life and Literary Death in Medieval Irish Tradition by Joseph Falaky Nagy
38. Satirical Narrative in Early Irish Literature by Ailís Ní Mhaoldomhnaigh
39. Lia Fáil: Fact and Fiction in the Tradition by Tomás Ó Broin
40. Irish Myths and Legends by Tomás Ó Cathasaigh
41. ‘Nation’ Consciousness in Early Medieval Ireland by Miho Tanaka
42. Bás inEirinn: Cultural Constructions of Death in Ireland by Lawrence Taylor
43. Ritual and myths between Ireland and Galicia. The Irish Milesian myth in the Leabhar Gabhála Éireann: Over the Ninth Wave. Origins, contacts and literary evidence by Monica Vazquez
44. Continuity, Cult and Contest by John Waddell
45. Cú Roí and Svyatogor: A Study in Chthonic by Grigory Bondarenko
46. Autochthons and Otherworlds in Celtic and Slavic by Grigory Bondarenko
47. The ‘Terror of the Night’ and the Morrígain: Shifting Faces of the Supernatural by Jacqueline Borsje
48. ‘The Otherworld in Irish Tradition,’ by John Carey
    
49. The Location of the Otherworld in Irish Tradition by John Carey
50. Prophecy, Storytelling and the Otherworld in Togail Bruidne Da Derga by Ralph O’ Connor
51. The Evil Eye’ in early Irish literature by Jacqueline Borsje and Fergus Kelly
52. Rules and Legislation on Love Charms in Early Medieval Ireland by Jacqueline Borsje
53. Marriage in Early Ireland by Donnchadh Ó Corráin
54. The Human Head in Insular Pagan Celtic Religion by Anne Ross
55. Gods in the Hood by Angelique Gulermovich Epstein
56. The Names of the Dagda by Scott A Martin
57. The Morrigan and Her Germano-Celtic Counterparts by Angelique Gulermovich Epstein
58. The Meanings of Elf, and Elves, in Medieval England by Alaric Timothy Peter Hall
59. Elves (Ashgate Encyclopaedia) by Alaric Timothy Peter Hall
60. The Evolution of the Otherworld: Redefining the Celtic Gods for a Christian Society by Courtney L. Firman
61. Warriors and Warfare – Ideal and Reality in Early Insular Texts by Brian Wallace
62. Images of Warfare in Bardic Poetry by Katharine Simms
63. Rí Éirenn, Rí Alban, Kingship and Identity in the Ninth and Tenth Centuries by Máire Herbert
64. Aspects of Echtra Nerai by Mícheál Ó Flaithearta
65. The Ancestry of Fénius Farsaid by John Carey
66. CELT (Corpus of Electronic Texts) – published texts
67. Mary Jones (Celtic Literature Collective) – translations

Printed Sources For The Above Articles:

1. The Gaelic Finn Tradition by Sharon J. Arbuthnot and Geraldine Parsons
2. An Introduction to Early Irish Literature by Muireann Ní Bhrolcháin
3. Lebar Gabala: Recension I by John Carey
4. The Irish National Origin-Legend: Synthetic Pseudohistory by John Carey
5. Studies in Irish Literature and History by James Carney
6. Ancient Irish Tales by Tom P. Cross and Clark Harris Slover
7. Early Irish Literature by Myles Dillon
8. Irish Sagas by Myles Dillon
9. Cycle of the Kings by Myles Dillon
10. Early Irish Myths and Sagas by Jeffrey Gantz
11. The Celtic Heroic Age by John T Koch and John Carey (Editors)
12. Landscapes of Cult and Kingship by Roseanne Schot, Conor Newman and Edel Bhreathnach (Editors)
13. The Banshee: The Irish Death Messenger by Patricia Lysaght
14. The Learned Tales of Medieval Ireland by Proinsias Mac Cana
15. The Festival of Lughnasa: A Study of the Survival of the Celtic Festival of the Beginning of Harvest by Máire MacNeill
16. Pagan Past and Christian Present in Early Irish Literature by Kim McCone
17. The Wisdom of the Outlaw by Joseph Falaky Nagy
18. Conversing With Angels and Ancients by Joseph Falaky Nagy
19. From Kings to Warlords by Katharine Simms
20. Gods and Heroes of the Celts by Marie-Louise Sjoestedt (trans Myles Dillon)
21. The Year in Ireland by Kevin Danaher
22. In Ireland Long Ago by Kevin Danaher
23. Irish Customs and Beliefs by Kevin Danaher
24. Cattle in Ancient Ireland by A. T. Lucas
25. The Sacred Trees of Ireland by A. T. Lucas
26. The Lore of Ireland: An Encyclopaedia of Myth, Legend and Romance by Dáithí Ó hÓgáin
27. Irish Superstitions by Dáithí Ó hÓgáin
28. Irish Folk Custom and Belief by Seán Ó Súillebháin
29. Armagh and the Royal Centres in Early Medieval Ireland: Monuments, Cosmology and the Past by NB Aitchison
30. Land of Women: Tales of Sex and Gender from Early Ireland by Lisa Bitel
31. Irish Kings and High-Kings by John Francis Byrne
32. Early Irish Kingship and Succession by Bart Jaski
33. A Guide to Early Irish Law by Fergus Kelly
34. Early Irish Farming by Fergus Kelly
35. A Guide to Ogam by Damian McManus
36. Ireland before the Normans by Dáibhí Ó Cróinín
37. Early Medieval Ireland: 400-1200 by Dáibhí Ó Cróinín
38. A New History of Ireland Volume I: Prehistoric and Early Ireland by Dáibhí Ó Cróinín (Editor)
39. Early Ireland by Michael J O’ Kelly
40. Cattle Lords & Clansmen by Nerys Patterson
41. Sex and Marriage in Ancient Ireland by Patrick C Power
42. Myths and Symbols in Pagan Europe by H R Ellis Davidson
43. The Lost Beliefs of Northern Europe by Hilda Ellis Davidson
44. Lady with a Mead Cup by Michael J Enright
45. Celtic Mythology by Proinsias Mac Cana