These are the great stories of Irish mythology — tales that have been told and retold for over a thousand years. They were first written down by monks in medieval Ireland, but the stories they recorded were already ancient.
Irish mythology doesn’t tell its stories in one place. They are spread across dozens of old manuscripts, grouped into cycles. Each section below covers one of those cycles. The stories here are drawn from manuscripts like the Book of the Dun Cow and the Book of Leinster — among the oldest written literature in any European language outside of Greek and Latin.
Cycle of the Gods (Mythological Cycle)
The oldest stories in Irish mythology. These cover the divine races who held Ireland before the ancestors of the Irish arrived — the Fir Bolg, the Tuatha Dé Danann, and the Fomorians. Presented here in the order they appear in the mythological timeline.
The Book of Invasions | Lebor Gabála Érenn | Leabhar Gabhála Éireann
The great mythological history of Ireland. It tells the story of six successive groups of people who took Ireland — from the biblical flood to the arrival of the Gaels. It’s not one text but a whole tradition, compiled and revised across centuries. Almost everything else in Irish mythology hangs off it.
The First Battle of Mag Tuired | Cáth Maige Tuired Éíne | Cath Maige Tuireadh (Céad)
The battle in which the Tuatha Dé Danann defeated the Fir Bolg and took Ireland. After a week of single combat by agreement, the two sides met in full battle. The Tuatha Dé Danann won — but their king Nuada lost his arm in the fighting, and under Irish law a king had to be physically whole. That one lost arm changed the entire course of the mythology.
The Second Battle of Mag Tuired | Cáth Maige Tuired | Cath Maige Tuireadh
The great war between the Tuatha Dé Danann and the Fomorians. The young warrior Lugh arrived at the court of the gods and was admitted because he could do more things better than anyone else there. In the battle he killed his own grandfather Balor — the Fomorian king with the lethal eye — with a sling-stone. One of the most detailed battle stories in early Irish literature.
The Children of Lir | Oidheadh Chlainne Lir | Oidheadh Chlainne Lir
One of the Three Sorrows of Irish Storytelling. Lir’s four children were transformed into swans by their jealous stepmother and condemned to spend nine hundred years on the waters of Ireland. They kept their human minds and voices the whole time. Their singing was so beautiful that people came from all over Ireland to hear it. They were freed when Christianity came to Ireland — but came out of the water as ancient, withered figures and died almost immediately.
The Children of Tuireann | Oidheadh Chlainne Tuireann | Oidheadh Chlainne Tuireann
One of the Three Sorrows of Irish Storytelling. The three sons of Tuireann killed Lugh’s father. Lugh sent them on eight impossible tasks across the world as payment for the death. They completed every single one — at enormous cost. On the last task they were mortally wounded. Lugh refused to heal them. They died together. A story about vengeance that doesn’t let you feel comfortable about it.
The Dream of Aengus | Aislinge Óenguso | Aislinge Aonghusa
One of the most beautiful stories in Irish mythology. The god Aengus Óg fell in love with a woman who appeared to him in a dream. He spent a year searching all of Ireland for her. She was Caer Ibormeith — a woman who lived half the year as a swan. When he found her on Samhain he turned himself into a swan to be with her. They flew away together and their singing put everyone who heard it to sleep for three days.
The Taking of the Fairy Mounds | Tochomlod inna Fer nÉ | Tochomlod na bhFear Dé
After the Tuatha Dé Danann were defeated by the Milesians, they didn’t leave Ireland. They went underground — into the fairy mounds, the síde. The Dagda divided the mounds among them. Aengus Óg talked his way into taking Newgrange from his own father. The Tuatha Dé Danann became the daoine sí — the fairy people — who shaped Irish supernatural tradition for the next thousand years.
The Battle of Tailtiu | Cath Tailten | Cath Tailteann
The final battle of the mythological invasions. The Milesians — the ancestors of the Irish — fought the Tuatha Dé Danann and defeated them. The Tuatha Dé Danann went underground. The Milesians took the surface world. The two peoples have shared Ireland, above and below, ever since.
Tuan mac Cairill | Immram Tuáin maic Cairill | Immram Thuáin Mhic Cairill
A man who lived through every invasion of Ireland by transforming into different animals — a stag, a boar, an eagle, a salmon. In his salmon form he was eaten and reborn as a human, carrying the memories of every age. When a monk asked him what he remembered, he told the whole story. A single witness to all of Irish history.
The Wooing of Étaín | Tochmarc Éataíne | Tochmharc Éadaóine
One of the greatest stories in Irish mythology. The jealous goddess Fuamnach transformed her rival Étaín into a fly. She was blown across Ireland on a magical wind, swallowed, and reborn as a human woman with no memory of who she had been. The god Midir spent lifetimes trying to get her back. In the end he won her from the High King in a game of chess, turned both of them into swans, and flew out through the roof of Tara. It ends without resolution — which is exactly the point.
Ulster Cycle
The oldest and most intense body of stories in Irish mythology. The Ulster Cycle is set in the Iron Age, at the court of King Conchobar at Emain Macha. Its central text — the Táin Bó Cúailnge — is the longest narrative in early Irish and one of the great epic texts of medieval Europe.
The Death of Cú Chulainn | Aided Con Culainn | Aidheadh Con Culainn
Every enemy Cú Chulainn had ever made combined against him. His sacred obligations were broken one by one. His horse wept tears of blood. His charioteer Láeg was killed before him. Mortally wounded, Cú Chulainn tied himself to a standing stone so he would die on his feet. The Morrígan landed on his shoulder as a crow — the signal to his enemies that the greatest warrior in Ireland was finally dead.
The Death of the Only Son of Aoife | Aided Óenfhir Aife | Aidheadh Óenfhir Aoife
Cú Chulainn had a son by the warrior-woman Aife during his training. Years later a young warrior arrived on the Irish shore and refused to give his name — he had taken an oath never to reveal it. Cú Chulainn fought him and used the gáe bolga. The boy died on the shore. As he was dying, he showed his father the ring. The Ulster Cycle at its most devastating.
The Birth of Cú Chulainn | Compert Con Culainn | Coimpeart Con Culainn
Cú Chulainn’s origin comes in two versions. In one, the god Lugh fathered him. In the other, his mother accidentally swallowed a mayfly. He was first named Sétanta. He became Cú Chulainn — the Hound of Culann — after he killed the smith Culann’s guard dog and offered to take its place until a new one could be trained.
Deirdre and the Sons of Uisneach | Deirdre agus Clann Uisneach | Deirdre agus Clann Uisneach
One of the Three Sorrows of Irish Storytelling. The druid Cathbad prophesied at Deirdre’s birth that she would destroy Ulster. The king Conchobar had her raised alone, planning to marry her himself. She fell in love with the warrior Naoise and fled with him and his brothers to Scotland. Conchobar lured them back with a false promise of safety. The brothers were killed on arrival. Deirdre died rather than live as the king’s wife.
Bricriu’s Feast | Fled Bricrenn | Fleadh Bhricreann
The troublemaker Bricriu set Ulster’s three greatest warriors — Cú Chulainn, Conall Cernach, and Laoghaire Buadhach — competing for the Champion’s Portion at a feast. The contest ended in the Beheading Game: each man had to let a giant behead him, on condition that the giant could take a return blow the next day. Only Cú Chulainn kept his side of the bargain. This story is the direct source of the Green Knight episode in Sir Gawain and the Green Knight.
The Exile of the Sons of Uisneach | Longas mac nUislenn | Loingeas Mac nUisleann
The foundational text of the Deirdre story. The killing of the sons of Uisneach on Conchobar’s orders drove Fergus mac Róich — the man who had promised them safe conduct — permanently into exile in Connacht. It set up the grievances that would weaken Ulster before the great cattle raid.
The Boyhood Deeds of Cú Chulainn | Macgnímhartha Con Culainn | Macgnímhartha Con Culainn
Before Cú Chulainn was old enough to join the adult warriors, he was already beating the entire boy-troop at Emain Macha on his own. He was told that a particular day would give him great fame but a short life. He chose fame without hesitating. Each early deed established the pattern of who he was — extraordinary, reckless, aware of what was coming, and going toward it anyway.
The Intoxication of the Ulstermen | Mesca Ulad | Meisce Uladh
After a feast, the Ulster warriors got so drunk that they drove through the night in their chariots with no idea where they were going. They ended up at the fortress of their enemy Cú Roí mac Dáire in Munster, who recognised them and let them eventually find their way home. The Ulster Cycle at its most sardonic.
Mac Da Thó’s Pig | Scéla Mucci Meic Da Thó | Scéla Muice Mhic Da Thó
The host Mac Da Thó promised his pig and his famous hound to both Ulster and Connacht at the same time. At the feast, the question of who had the right to carve the pig started a series of increasingly violent arguments about who was the greatest warrior in Ireland. The hound ran away in the chaos. One of the funniest — and darkest — stories in the whole cycle.
The Sick Bed of Cú Chulainn | Serglige Con Culainn | Serglige Con Culainn
Cú Chulainn was struck down by a supernatural sickness and summoned to the Otherworld by the goddess Fand. He spent a month with her. His wife Emer found out and came with armed women to confront them. Fand chose to leave. Manannán mac Lír shook his cloak between Fand and Cú Chulainn so neither would remember the other. The druids gave both Cú Chulainn and Emer a drink of forgetfulness. It ends in grief on every side.
The Táin Bó Cúailnge | Táin Bó Cúailnge | Táin Bó Cúailnge
The great cattle raid. Queen Medb invaded Ulster to steal the Brown Bull of Cooley. The men of Ulster were paralysed by Macha’s curse and couldn’t fight. Cú Chulainn held the ford alone against Connacht’s entire army while they recovered. The emotional centrepiece is his three-day fight with his best friend Fer Diad — which he wins and which destroys him at the same time.
The Cattle Raid of Fróech | Táin Bó Fraoch | Táin Bó Froaich
One of the most beautifully written texts in the Ulster Cycle. The warrior Fróech mac Idath came to court Findabair, daughter of Medb and Ailill. The description of his beauty when he swam in the river before the Connacht court is one of the most striking passages of descriptive writing in early Irish literature.
The Destruction of Da Derga’s Hall | Togail Bruidne Da Derga | Tógáil Bruidne Da Dearga
The High King Conaire Mór broke every sacred obligation he was bound by — through bad luck, impossible choices, and one bad decision after another. A supernatural woman told him he would die at the door of a certain hall. His enemies surrounded the hall and burned it. One of the great meditations in Irish literature on fate and what happens when a king violates the duties of kingship.
The Wooing of Emer | Tochmarc Emire | Tochmharc Éimhear
Cú Chulainn chose Emer because she alone among all the women of Ireland matched him in wit, beauty, and courage. Her father sent him to train with Scáthach in Scotland, hoping he would be killed. Instead he came back as the greatest warrior of his generation, stormed Forgall’s fortress, and took Emer. The story is as much about what he became on the way as it is about the prize at the end.
Fenian Cycle
The most widely loved stories in Irish mythology. The Fenian Cycle follows Fionn mac Cumhaill and the Fianna. Where the Ulster Cycle is intense and tragic, these stories move between adventure, comedy, loss, and love. They spread across Ireland, Scotland, and the entire diaspora in both written manuscripts and oral tradition.
The Colloquy of the Old Men | Acallam na Senórach | Agallamh na Seanórach
The longest surviving Fenian text. The aged survivors of the Fianna — Caílte mac Rónáin and Oisín — travel with St. Patrick across Ireland. At every mountain, lake, and hill they pass, Caílte tells Patrick the story connected to it. It is at once a record of the entire Fenian tradition and a meditation on memory, loss, and a world that is gone.
The Death of Diarmuid | Aided Diarmada | Aidheadh Dhiarmada
Diarmuid was hunting on the slopes of Ben Bulben when he met a magical boar — the reincarnation of his own foster-brother. He killed the boar but was fatally gored by its venomous bristles. Fionn was there. He had the power to heal Diarmuid by carrying water in his cupped hands. He lifted the water twice and let it fall. Oscar shamed him into trying again. When he returned, Diarmuid was dead.
The Hall of the Rowan Trees | Bruidhean Chaorthainn | Bruíon Chaorthainn
The Fianna were lured into the Hall of the Rowan Trees and trapped — the floor enchanted, the doors sealed, their bodies fixed in their seats. Diarmuid Ua Duibhne was outside and had to fight off wave after wave of attackers while trying to find a way to free his companions.
The Battle of Knocknarea | Cath Cnoc na Rí | Cath Chnoc na Rí
A battle fought by the Fianna on the slopes of Knocknarea in Co. Sligo — the hill with Queen Medb’s great cairn on top. It ties the Fenian tradition to one of the most atmospheric and important sites in the west of Ireland.
The Battle of Ventry | Cath Finntrágha | Cath Finnthrágha
A king who called himself the King of the World invaded Ireland at Ventry Harbour in Co. Kerry and fought the Fianna for a year and a day. Fionn and his men held the shore against the entire world. The harbour where the battle was said to have been fought is still there.
The Battle of Gowra | Cath Gabhra | Cath Ghabhra
The last battle of the Fianna. The High King Cairbre Lifechair brought his forces against them and broke them. Oscar — the greatest fighter the Fianna ever had — killed Cairbre in single combat but was mortally wounded doing it. Fionn, kept from the battlefield, saw a wave of blood crest over the hill and knew without being told that Oscar was down. He wept. The only time the cycle records it.
The Feast at Conan’s House | Fled Tighe Chonainn | Fleadh Tigh Chonainn
The Fianna were trapped in Conan’s house by supernatural enemies and had to fight their way out through a night of attacks. Conan Maol — the Fianna’s comic troublemaker — managed to make the situation worse more than once, as he always did.
The Boyhood Deeds of Fionn | Macgnímhartha Finn | Macgnímhartha Fhinn
The foundation of the Fenian Cycle. It covers Fionn’s birth after his father’s death, his childhood in hiding, his years of training, his time with the druid-poet Finnéces, and the moment he accidentally ate the Salmon of Knowledge and received all the wisdom in the world. By the end of it he has his name, his power, and his identity.
Oisín in Tír na nÓg | Oisín i dTír na nÓg | Oisín i dTír na nÓg
Niamh of the Golden Hair came from the Land of Youth on a white horse and asked Oisín to go back with her. He went. Three years passed there — three hundred years in Ireland. When he returned, the Fianna were gone and everyone he knew was dead. He fell from his horse, touched the ground, and aged three centuries in an instant. The great elegy of the Fenian Cycle.
The Hunt of Slieve Cuilinn | Seilg Sliabh Cuilinn | Seilg Shliabh Cuilinn
A woman lured Fionn to the lake on Slieve Cuilinn to retrieve her ring from the water. He dived in and came out as an old man — grey, withered, stripped of his strength. The Fianna eventually restored him through their magic. The lake on Slieve Cuilinn is still there.
The Pursuit of the Hard Servant | Tóraigheacht an Ghiolla Dheacair | Tóraíocht an Ghiolla Dheacair
A giant ugly stranger arrived at Fionn’s hall with a lame, miserable-looking horse. Some of the Fianna mounted the horse as a joke. It ran with them across Ireland and into the sea, carrying them to the Otherworld. Fionn and the rest had to follow and fight their way through the underwater world to get them back.
The Pursuit of Diarmuid and Gráinne | Tóraigheacht Dhiarmada agus Ghráinne | Tóraíocht Dhiarmada agus Ghráinne
On her wedding night to Fionn, Gráinne placed a magical compulsion on Diarmuid to flee with her. For sixteen years Fionn hunted them across every county in Ireland. When it ended, it ended with Diarmuid’s death, Fionn’s deliberate choice not to save him, and Gráinne’s silence.
Cycle of the Kings
These stories cover the long period between the mythological age and the arrival of Christianity — a world of High Kings, dynastic struggles, and the Otherworld pressing constantly against the edge of the human world. Some of these kings were real people. All of their stories reach into the supernatural.
The Death of Diarmait mac Cerbaill | Aided Diarmata meic Cerbaill | Aidheadh Diarmata Mhic Cearbaill
The death of the last pagan High King of Ireland. A prophecy said he would die by a triple death — drowning, burning, and wounding at the same time. He died in a burning hall, drowned and stabbed. The story sits right at the hinge between the old world and the new, and it doesn’t entirely look away from the tragedy of what was ending.
The Night Vigil of Fingen | Airne Fíngein | Airne Fíngein
The king Fingein mac Luchta kept watch on the feast of Samhain and received prophetic knowledge of everything happening across Ireland that night — every fire, every king, every sacred site. The text is a remarkable snapshot of how the whole mythological geography of Ireland was understood at the time it was written.
The Phantom’s Frenzy | Baile in Scáil | Baile an Scáil
A supernatural horseman led the High King Conn of the Hundred Battles to an Otherworld hall. Inside, a goddess sat beside a great vat pouring drink. A figure representing Lugh named every future king of Ireland in order, each one receiving a cup from the goddess’s hand. One of the clearest images in Irish mythology of what it meant to be the rightful king.
The Boroma | Bóroma | Bóroma
The story of a cattle tribute imposed on Leinster by the High Kings, and the generations of battles, deaths, and resistance that followed. It went on for centuries before a saint finally talked the High King into abolishing it. A long, patient story about what a grievance can do to a people over time.
The Frenzy of Sweeney | Buile Suibhne | Buile Shuibhne
The king Suíbhne was cursed by a saint at the Battle of Mag Rath and driven mad. He fled the battlefield and spent years living in the wild places of Ireland and Scotland, sleeping in trees. The poems he composed during that time — describing the natural world around him — are among the most beautiful in the entire Irish tradition.
The Battle of Allen | Cath Almaine | Cath Almaíne
A major battle fought in Co. Kildare in 722 AD — one of the great victories of Leinster over Ulster in the long dispute over the Boroma tribute. The Leinster king Murchad mac Brain killed the High King Fergal mac Máele Dún. One of the few texts in the cycle where the history and the myth almost exactly overlap.
The Battle of Mag Mucrama | Cath Maige Mucrama | Cath Maighe Mucrama
The battle where the High King Art mac Cuinn was killed by Lugaid mac Con. The night before, knowing he would die, Art slept with a woman named Achtan. Their son Cormac mac Airt — conceived that night — grew up to drive out the usurper with a single correct legal judgement and became the greatest High King in Irish tradition.
The Battle of Mag Rath | Cath Maige Rath | Cath Maighe Rath
One of the largest battles in early Irish tradition, fought in 637 AD near Moira in Co. Down. It is the battle that drove the poet Suíbhne mad — the chaos of the slaughter broke him and he fled into the wild. One of the texts where a real historical event and a mythological story are tangled so tightly they can’t be separated.
The Birth of Mongan | Compert Mongáin | Coimpeart Mhongáin
How Mongan mac Fiachna came to have Manannán mac Lír as his true father. Manannán came to Mongan’s mother in the form of her husband while the husband was away at war. Mongan grew up with the gifts of shapeshifting and prophetic knowledge, and was said to be a reincarnation of Fionn mac Cumhaill.
The Adventure of Art | Echtra Airt meic Cuinn | Eachtra Airt Mhic Cuinn
Art mac Cuinn was banished from Tara and had to fight through the Otherworld to win the woman Delbchaem from a series of supernatural guardians. At every stage he was tested. The story is a complete hero’s journey compressed into one tale, with sovereignty — both the woman and the kingship — as the prize at the end.
The Adventure of Connla | Echtra Chonle | Eachtra Chonle
A woman from the Otherworld came to the court of Conn of the Hundred Battles and called away his son Connla. Conn’s druid drove her off, but before she left she threw Connla an apple. For a whole month he ate nothing else and the apple never shrank. When she came back, he went with her. He was never seen again.
The Adventure of Loegaire | Echtra Laegaire | Eachtra Laoghaire
The Ulster warrior Loegaire mac Crímthainn followed a fairy man into the Otherworld to help him in a battle and win back his wife. When it was over, Loegaire chose to stay in the Otherworld rather than return. He sent a message back to his people telling them not to follow him.
The Adventure of the Sons of Eochaid | Echtra mac nEchach | Eachtra Mac nEachach
The sons of Eochaid Mugmedón each had to get water from a well guarded by a hideous supernatural woman. Each brother turned away in disgust — except Niall, who embraced her. She transformed into a beautiful woman and told him he would be king. One of the clearest and most powerful versions of the sovereignty test in Irish mythology.
Cormac’s Journey to the Land of Promise | Echtra Cormaic i Tír Tairngiri | Eachtra Chormaic i dTír Tairngire
Cormac mac Airt followed a mysterious horseman into the Otherworld and found his wife and children there. Manannán mac Lír revealed himself as host and gave Cormac a golden cup that shattered when three lies were spoken over it and came back together at three truths. The cup of truth became one of Cormac’s most famous attributes.
The Kinslaying of Rónán | Fingal Rónáin | Fingal Rónáin
The king Rónán’s young wife falsely accused his son of trying to seduce her. Rónán had his son killed. When he discovered the truth, he killed her — and his grief destroyed him. The same story appears in many cultures, including the Greek myth of Phaedra and Hippolytus. The Irish version is told with a directness and economy that is entirely its own.
The Feast of the Fort of the Geese | Fled Dúin na nGéd | Fleadh Dúin na nGéd
A feast held on the River Boyne where a series of political and supernatural events unfold around the High King Domhnall mac Aedo. It is one of several feast tales in the Irish tradition where hierarchy is displayed, tested, and sometimes violently disrupted.
Niall of the Nine Hostages | Niall Noígiallaich | Niall Naói nGiallach
How Niall of the Nine Hostages proved his right to the kingship, took hostages from five provinces and abroad, and built the dynasty that dominated Ireland for five centuries. The founding document of the Uí Néill lineage.
The Story of Cano mac Gartnáin | Scéla Cano meic Gartnáin | Scéla Cano Mhic Gartnáin
A love story between the Scottish prince Cano mac Gartnáin and the Irish woman Créd. Cano kept his soul in a stone — while the stone survived, he lived. On the night they were finally to meet, a jealous rival smashed it. Cano died in Scotland three days later. Créd died on the spot. A love story with no survivors.
The Wooing of Becfhola | Tochmarc Becfhola | Tochmharc Becfhola
Becfhola slipped away from her husband’s side in the night to meet an Otherworld man named Flann. She arrived to find him fighting a battle. While she waited, the night passed in an instant, and when she returned to Tara it seemed as if no time had passed at all. Time running differently in the two worlds is one of the recurring facts of Irish Otherworld encounters.
The Destruction of Da Choca’s Hall | Togail Bruidne Da Choca | Tógáil Bruidne Da Choca
The Ulster king Cormac Conn Longas sought shelter at Da Choca’s hall and was killed in a burning. The story is full of bad omens and broken obligations — signs that were ignored or couldn’t be avoided. Another meditation on fate and what happens when a king violates the duties of hospitality.
Immrama — The Voyage Tales
The immrama are a genre unique to early Irish literature. A crew of men sets out into the Atlantic, visits a series of strange islands, and encounters the supernatural in various forms. Each island is different — some beautiful, some terrible, some impossible to understand. The ocean itself becomes a place where the normal rules don’t apply. The four surviving immrama are among the most imaginative texts from early medieval Europe.
The Voyage of Bran | Immram Brain maic Febail | Immram Bhrain mhic Feabhail
The oldest of the voyage tales. A woman from the Otherworld gave Bran a silver branch and described a paradise across the sea. He set out with twenty-seven companions, visited various islands, and eventually reached the Island of Women, where they stayed for what seemed like a year. When one of the crew tried to return to Ireland, he turned to ash the moment he touched the ground. Bran called out their names from the sea and sailed away. The oldest text in the genre, and still one of the best.
The Voyage of Máel Dúin | Immram Curaig Máele Dúin | Immram Churraígh Mháel Dúin
The longest and most elaborate of the voyage tales. Máel Dúin set out to avenge his father’s murder and visited thirty-three islands along the way — each one with its own distinct wonder or danger. Giant ants. A revolving fortress. A bridge of glass. An island where time moves differently. The journey gradually shifts from a mission of vengeance to something more like a pilgrimage. When he finally finds his father’s killer, he forgives him.
The Voyage of Snedgus and Mac Riagla | Immram Snedgusa ocus Maic Riagla | Immram Snedgus agus Mhic Riagla
Two monks from Iona set out on a penitential voyage and visited a series of supernatural islands, including one populated by the souls of the men of Ireland living in the form of birds. They received prophecies about the future of Ireland from them. The most explicitly Christian of the voyage tales — less an adventure than a spiritual journey.
The Voyage of the Uí Chorra | Immram Curaig Ú Corra | Immram Churraígh Ú Chorra
Three brothers who had spent their lives causing trouble finally converted and set out on a penitential voyage to make up for it. Each island they visited showed them a different aspect of what happens after death — the punished, the rewarded, the waiting. The most morally direct of the voyage tales, using the journey as a frame for a vision of divine justice.
See also: Irish Gods | Irish Goddesses | Irish Heroes | Irish Mythical Creatures