Irish Mythology

Illuminated manuscript, by Patrick Lordan

Illuminated manuscript, by Patrick Lordan

Mythology helps us see how a cultures’ mind ticks. Not just what it believes, but also how these beliefs fit into society, showing us how society should (ideally) – or shouldn’t – work. On the one hand, understanding the myths helps us understand how the society works; on the other hand, the more we understand the society and culture of a people, the more we understand the mythology.

In a sense, then, mythology can be seen as a reflection of society and its religion and vice versa. The myths and tales of Ireland are therefore extremely important for understanding the way in which the gods acted and interacted, and how the Irish perceived them to be. Naturally this can also helps us understand how they might fit into our own spirituality. Unfortunately there is very little evidence in the myths that describes specific ritual practice.

Since the tales were written down during the Christian period, usually by monks, there is often a mishmash of seemingly pagan and Christian content in the myths that have survived. In many cases the Christian content can be easily spotted, but sometimes it isn’t as simple or straightforward as that.1 This is something worth remembering but for now it would be best to familiarize yourself with some of the most important tales before going on to deal with them in more depth.

The Myths

Since there are hundreds of Irish myths and legends it can often be difficult to know where to start and how to interpret them all. Generally, they are therefore split into four different cycles (or groups) of tales that have particular characters or themes in common. These cycles are:

  • The Mythological Cycle
  • The Ulster Cycle
  • The Fenian Cycle
  • The Historical Cycle2

Breaking down the tales into these cycles makes them easier to deal with and discuss, analyze and interpret to the modern student or scholar, but the medieval Irish poets themselves broke the tales down according to the main events or deeds that occurred in the tale. These subjects fell under the following headings:

Types Old Irish (pl/sg)

  • Destructions (togla/togail)
  • Cattle raids (tána/táin)
  • Wooings (tochmarca/tochmarc)
  • Battles (catha/cath)
  • Feasts (fessa/feis)
  • Adventures (echtrada/echtrae)
  • Elopements (aitheda/aithed)
  • Plunderings (airgne/argain)
  • Floodings (tomadma/tomaidm)
  • Visions (físi/fís)
  • Loves (serca/serc)
  • Migrations (tochladada/tochomlod)
  • Terrors (uatha/uath)
  • Voyages (immrama/immram)
  • Violent deaths (aideda/aided)
  • Sieges (forbassa/forbais)
  • Conceptions and births (coimperta/compert)
  • Frenzies (buili/buile)3

The most popular characters generally had tales that came under several of these headings (as well as other subjects not on this list) so that many of the major parts of their life were covered – their conception or birth, the wooing of their intended wife, their violent death and so on.

The poets of medieval Ireland were supposed to memorize all the tales that fell under these headings so that they could be recited “to the kings and chiefs of Ireland.”4 The Book of Leinster also tells us that there were 350 tales that fell under all the different headings, divided into 250 prime stories (primscéla) and 100 secondary stories (foscéla). All poets were supposed to memorize the prime stories, but only the highest ranks of ollam, anrad, clí and cano (out of seven ranks in total)5 were supposed to be able to recite the secondary stories as well. Only 187 primary stories have survived in the medieval Irish manuscripts, but no secondary stories have been preserved at all.6

For our purposes, we’ll keep things simple and stick with the modern way of dividing the stories into the four cycles so we can take a look at what each cycle is about, and which tales are a good place to start reading for each of them. A lot of these tales are available online, but suggested translations to buy and some further reading will also be given at the end.

Generally speaking the Mythological and Ulster Cycles are regarded as being the most relevant to those who are interested in the pre-Christian society of Ireland because they are often thought to seem “earlier in feeling and more characteristically Celtic.” At least one Celtic scholar has gone so far as to say that the Ulster Cycle in particular is a “window on the Iron Age” of Ireland because its content, with heroes riding chariots, druids being the right-hand men of kings and so on, seems more “authentically” pre-Christian than any other cycle.7 This is not to say that the other cycles are felt to be irrelevant, however, or that such claims for the Ulster Cycle means that we should take those stories at face value.

The Mythological Cycle

The Mythological Cycle deals with many of the gods of Ireland and defines the mythical landscape and history of Ireland – how Ireland came to be.8 It includes the closest story Ireland has to its own creation myth (though the actual creation part is missing, and as it stands now it may be considered to be an origin myth, describing where and how the Irish people came to be), which is set loosely within a Biblical framework – probably in an attempt to put the pagan Irish pre-history in a more Christian context.9

This story is the Lebor Gabála Érenn (“The Book of Invasions”) and it describes the six different waves of invaders who came and settled their people in Ireland. These invaders were:

  • The people of Cessair
  • The people of Parthalón
  • The people of Nemed
  • The Fir Bolg
  • The Tuatha Dé Danann
  • The Sons of Míl

Cessair’s people arrived in Ireland before the Biblical Flood and are said to have been wiped out by the waters, all except for Fintan mac Bochra who is said to have lived through all the subsequent invasions until he met Fionn mac Cumaill and they both went into the afterlife.

Parthalón’s people came and settled Ireland after the Flood but were eventually wiped out by a plague. Then came the people of Nemed, who became subject to the Fomorians and tried to rise against them. The Nemed were not successful in their rebellion, and after sailing in ships to the islands where the Fomorians lived, only one boat of survivors was left, numbering thirty men in all. Some of the survivors are said to have fled to Greece, while the rest went ‘north’.

The descendants of the Nemed who went to Greece eventually came back to Ireland as the Fir Bolg (“Men of Bags”), and they lived there until the next wave of invaders, the Tuatha Dé Danann (“People of the Goddess Danu”), arrived and fought with them for Ireland. The Tuatha Dé, being victorious, made themselves at home until they were ousted by the Sons of Míl who are said to have become the ancestors of the Irish people. After losing to the Sons of Míl, the Tuatha Dé Danann eventually agreed to split Ireland into two, so that the Sons of Míl governed everything above ground, while the Tuatha Dé governed everything below ground. The Tuatha therefore retreated into the hills and mounds of Ireland, and eventually became known as the people of the síde.

Of all the invaders of Ireland outlined in the Lebor Gabála Érenn, the Tuatha Dé Danann are the most important to the Mythological Cycle as a whole, being the central characters to it. Unlike the central characters of other cycles, the Tuatha Dé appear frequently in tales outside of the Mythological Cycle, often providing help or hindrance to the main protagonist of the tale.

There are several tales featuring the Tuatha Dé Danann that are important to the Mythological Cycle (see below), but there are also other sources that are not considered to be part of the cycle which are of equal significance to them; the Dindshenchas (Placename folklore) gives details of how places in Ireland got their names and the Tuatha Dé Danaan are often mentioned in the tales, while the Coir Anmann (“The Fitness of Names”) describes how characters from history, pseudo-history and literature got their names. In a similar vein, the Banshenchas (“Lore of Women”) describes the lore associated with some important women in history and literature.

All of these sources can be considered to be a supplementary body of literature to the Mythological Cycle that can further help our understanding of the Tuatha Dé Danann and their significance to the Irish.

Further reading:
The Book of Invasions
The Taking of the Síd
The Battle of Mag Tured
The First Battle of Mag Tured10
The Dream of Oengus
The Wooing of Etain
The Metrical Dinnshenchas
Bansenchas (link to part one only)

The Ulster Cycle

The characters of the Ulster Cycle were evidently the most popular in medieval Ireland, since there are more tales in this group than any other cycle – around 80 tales in all, including the various different versions of some of the stories.

These tales focus on the exploits of the men of Ulster – in particular their hero Cú Chulainn – during the reign of king Conchobar mac Nessa, which is thought to have been set some time around the first century BC. The men of Ulster – the Ulaid – fought with their neighbours, did heroic deeds, and especially in the case of Cú Chulainn, lived fast and died young. The most important tale to the cycle in the Táin Bó Cuailnge, which tells of how the Queen of Connacht, Medb, went on a cattle raid against the Ulaid in order to obtain their best bull – the best bull in all of Ireland.

Of all the Irish myths, the Táin is the longest and most developed in terms of trying to provide an extended narrative – giving background stories and underlying motives for the main characters in the tale, particularly the hero Cú Chulainn who is shown to have semi-divine origins (his father was Lug of the Tuatha De Danann). Medb, the Queen of Connacht, is thought to be a goddess of sovereignty – a representation of the land itself to whom an Irish king was traditionally married – and her actions in the tale are as important to understanding early medieval Irish society as they are to our understanding of how kingship was meant to work (more on both later).

Further reading:
Táin Bó Cuailnge
The Wasting Sickness of Cú Chulainn
The Tidings of Mac Da Tho’s Pig
The Destruction of Da Derga’s Hostel
The Labour Pains of the Ulaid
The Exile of the Sons of Uisliu
The Adventures of Nera
The Death of Conchobar

The Fenian Cycle

Sometimes referred to as the Ossianic Cycle, this group of tales centres around the exploits of Fionn mac Cumaill and his war band. The Fenian Cycle gets its alternative name from Oisín, or Ossian, son of Fionn, who is said to have written many of the tales. The cycle itself is supposed to be set in the third century AD during the reign of a (probably) historical king, Cormac mac Airt.11

Fionn is portrayed as not just a leader of a band of warriors, but also a seer with the power of prophecy and a poet. He is said to have gained these powers after burning his thumb while tending a cauldron that was cooking the Salmon of Wisdom and after the tasting the salmon, it is said that Fionn simply needed to chew on his thumb whenever he sought supernatural knowledge.

The stories that make up the Fenian Cycle are magical and supernatural in focus like the tales of the Mythological Cycle (with many characters of the sidhe appearing in this cycle as well), but also heroic and focused on warrior ideals like the Ulster Cycle. In some respects, the cycle might be regarded as being a bridge or synthesis between the two.12

Fionn, being a poet and a seer, is often regarded as being particularly important to anyone interested in these roles within Gaelic Reconstructionism. In addition, Fionn’s war band was generally referred to as the fiana – ‘a band of roving men whose principal occupations were hunting and war.’ The tales focus on fianaigheacht – the lore of the fiana – such as the ordeals and training a man might have to go through to become a fian, and so the cycle is also important to anyone interested in the ideals and training of warriors.

Further reading:
Colloquy of the Sages (pdf)
Boyhood Deeds of Fionn
How Fionn Found His Knowledge
The Fairy Palace of the Yew Trees
Fionn and the Man in the Tree
The Pursuit of Diarmid and Grainne
The Death of Fionn

The Historical Cycle

This final group of tales focuses on several different historical characters (usually kings) of Ireland. The association with kings here means that the cycle is sometimes referred to as the Cycle of the Kings, but whichever label you prefer the point of it is that these are tales that are dealing with supposedly historical, rather than purely mythological, figures.

Sometimes this cycle is broken down into further sub-cycles that concentrate on specific kings – Conn Cétchathach (“Conn of the Hundred Battles”), Cormac mac Airt, and Mongán mac Fiachnai, for example – but many of the kings who are featured don’t have enough tales to make a cycle of their own so we’ll keep things simple and stick with just the broader heading.

Regardless of their (alleged) historical roots, the kings featured in these tales are just as mythologised as another of the characters in other myths, and over all we find the myths of the Historical Cycle incorporating all of the usual symbolism and motifs you might expect. They can’t, therefore, be assumed to be biographical in a particularly literal sense, though they are informative and illuminating nonetheless. Generally speaking, the cycle explores the ideals and concepts of kingship in Irish society – issues of what made a good king or a bad king, and how they should behave.

To the Irish, a king was supposed to demonstrate certain things at all times. A good king was supposed be generous, courageous and wise, showing good judgment in all matters. The king’s ‘rightful’ rule was supposed to result in peace and plenty for his people, whereas an unjust rule would result in the opposite.13 Kingship was therefore a kind of contract between the king and his people, and the breaking or making of this contract is shown in Irish myth – but particularly the tales of the Historical Cycle – in various ways.

Sometimes the concept of sovereignty is shown as a woman. She might appear before potential kings as a hideous old hag demanding a kiss or sex so that they can pass her and be on their way; failure to kiss or sleep with the hag means the would-be king has failed to show good judgment, and he is no longer eligible to be king. The person who does as he is asked finds the hideous hag magically transformed into a beautiful woman; her condition changes from a barren old woman to a fertile, beautiful young woman. She is not just the concept of sovereignty, the right of the king to rule over his land and people; the sovereignty goddess is a representation of that land.14

This cycle is therefore particularly important in understanding the way in which the Irish viewed their relationship with the land, elements of which were generally personified by goddesses.

Further reading:
The Battle of Mag Mucrama
The Adventures of the Sons of Eochaid Mugmedon
The Battle of Cairn Conaill (pdf)
The Frenzy of Suibhne
The Adventures of Connla

Suggested reading

The following books are well worth reading and fairly straightforward, but if you’re on a budget and want to buy the most helpful then the first two books will probably be the most useful. Even so, all of them should be easily requested through your library if they don’t stock them already, so you don’t have to spend a lot of money.

The final three books on the list are worth reading in spite of the fact that translations of both tales are readily available online. These three books are recommended because they are considered to be reliable translations of the tales, but they also have useful notes with them that help explain some of the more obscure stuff that goes on in the tales. They are both usually available at very reasonable prices through online bookstores if you want to buy them.

Alwyn and Brinley Rees, Celtic Heritage: Ancient Tradition in Ireland and Wales (New York: Thames and Hudson, 1989)
Proinsias MacCana, Celtic Mythology (Hamlyn, London 1970)
Jeffery Gantz, Early Irish Myths and Sagas (London: Penguin Books, 1981)
Marie-Louise Sjoestedt, Celtic Gods and Heroes (Dover Publications, 2000)
T. P. Cross and C. H. Slover, Ancient Irish Tales (Rowman & Littlefield, 1969)
John T. Koch and John Carey, The Celtic Heroic Age: Literary Sources for Ancient Celtic Europe and Early Ireland and Wales (Celtic Studies Publications, Inc, 2003)
Thomas Kinsella, The Táin (Oxford: Oxford University Press, 1970)
Ciaran Carson, The Táin, (Penguin Classics, 2007)
Elizabeth A. Gray, Cath Maige Tuired: Second Battle of Mag Tuired (Dublin: Irish Texts Society, 1983)


Byrne, Francis John: Irish Kings and High-kings (B T Batsford, 1973).
Calder, George: Auraicept na N-Éces: The Scholar’s Primer (John Grant, Edinburgh, 1917)
Gantz, Jeffrey: Early Irish Myths and Sagas (Penguin, 1982)
Jackson, Kenneth Hurlstone: The Oldest Irish Tradition: A Window on the Iron Age (Cambridge University Press, 1964)
Jaski, Bart: Early Irish kingship and succession (Four Courts Press, 2000).
Kelly, Fergus: A Guide to Early Irish Law (Dublin, 1995).
Mac Cana, Proinsias: Celtic Mythology (Hamlyn, London, 1970)
McCone, Kim: Pagan Past and Christian Present in Early Irish Literature (Maynooth Monographs, 1990)
Rees, Alwyn and Brinley: Celtic Heritage: Ancient Tradition in Ireland and Wales (New York: Thames and Hudson, 1961)
Sjoestedt, Marie-Louise: Celtic Gods and Heroes (Dover Publications, 1949)


1 See for example Kim McCone, Pagan Past and Christian Present in Early Irish Literature (Maynooth Monographs, 1990).

2 Rees and Rees, Celtic Heritage, 1961, p26.

3 Rees and Rees, Celtic Heritage, 1961, p208.

4 Ibid.

5 Calder,Auraicept na N-Éces: The Scholar’s Primer, 1917, pXX. The other (lower) ranks were doss, macfuirmid and foclóc.

6 Rees and Rees, Celtic Heritage, 1961, p208.

7 Gantz, Early Irish Myths and Sagas, 1982, p26, and Kenneth Jackson’s The oldest Irish tradition: A window on the Iron Age, 1964.

8 Sjoestedt, Celtic Gods and Heroes, 1949, p1.

9 Rees and Rees, Celtic Heritage, 1961, p 95.

10 The First Battle of Mag Tured is thought to have been composed at a later date to provide a background to the events of The Second Battle of Mag Tured, so the distinction is only usually made with the First Battle of Mag Tured to distinguish it from its predecessor.

11 Rees and Rees, Celtic Heritage, 1961, p26.

12 Rees and Rees, Celtic Heritage, 1961, p67.

13 MacCana, Celtic Mythology, 1970, p117. See also Byrne, Jaski and Kelly.

14 See for example the The Adventures of the Sons of Eochaid Mugmedon.