Irish folklore and mythology: banshees, the púca and the Tuatha Dé Danann

Ireland kept its oldest stories alive by telling them in kitchens. Monks wrote some down, schools preserved others, and the rest survived in place names, wells and hills that people still point to. This edition of Mythical Mondays follows the island's stories from the age of invasions to the ghosts that linger at the edge of a wake.

First published in August 2026.

The people who came, and the people who went under

Irish mythology begins with arrivals. The Lebor Gabála Érenn, a medieval compilation of older traditions, describes a sequence of peoples who reached Ireland, each displacing the one before. The most memorable are the Tuatha Dé Danann, a race of skilled, god-like beings who came from the north with four treasures: the Lia Fáil, the stone that cried out beneath a rightful king; the spear of Lugh; the sword of Nuada; and the cauldron of the Dagda, which never ran empty.

They were beaten by the Milesians, ancestors of the Gaelic Irish, and withdrew into the sídhe — the mounds and hollow hills. In later tradition they became the aos sí, the people of the mounds, who still live beneath the landscape. Newgrange, the great passage tomb in the Boyne Valley, was identified as Síd in Broga, home of the Dagda and his son Aengus. The story explains a monument older than memory: the gods did not disappear, they simply moved underground.

The hero of Ulster

The Táin Bó Cúailnge, the Cattle Raid of Cooley, is the central epic of the Ulster Cycle. Queen Medb of Connacht wants the great brown bull of Ulster, and her armies march north to seize it. The men of Ulster are laid low by a curse, so only the teenage hero Cú Chulainn can defend the province, fighting champion after champion at fords and passes while the Morrígan, goddess of battle, circles him as an eel, a wolf and a heifer.

Cú Chulainn is no clean hero. He is beautiful and terrifying, bound by geasa — personal prohibitions that function like fate — and liable to a battle frenzy in which he cannot tell friend from enemy. In the end his enemies trick him into breaking his geasa, and he ties himself to a standing stone so that he will die upright, facing them. The story is brutal, funny and intensely local: the fields and fords it names are real places along the border of Ulster and Leinster.

The four swans

One of the most haunting Irish tales is the fate of the four children of Lir, king of the Tuatha Dé Danann. Their stepmother Aoife, jealous of the king's love for them, takes them to a lake and turns them into swans with a druid's wand. She sets the terms herself: they keep human speech and human minds, but must spend nine hundred years as swans in three places — Lough Derravaragh, the Sea of Moyle between Ireland and Scotland, and Inish Glora off the Mayo coast.

It is a meditation on time and loss. The children are still swans when Christianity arrives, and a monk hears them singing and records their story. When the spell finally breaks they are ancient, and they die soon after being baptised. Visitors to Lough Derravaragh, a lake in County Westmeath, are still told that the four swans were last seen there.

Messengers and neighbours

The banshee

The banshee (bean sídhe, woman of the mounds) is often pictured as a screaming ghost, but Irish tradition is more specific: she is a female spirit attached to particular families, who appears or is heard keening before a death. She does not cause the death and is not necessarily hostile. She is a messenger, and the families she follows — the O'Neills, the O'Briens, the O'Connors and others — are named in the tradition.

Her cry is a low, mournful keening, sometimes heard on three nights running. The image draws on a real practice: the bean chaointe, the professional mourning woman who led the keening at Irish funerals. The banshee is what happens when that human role is projected into the landscape — grief given a voice and a place to stand.

The pooka, the merrow and Fionn

Not every Irish spirit is grand. The pooka (púca) is a shape-shifter, often a black horse with yellow eyes, that can carry a rider through the night or leave him in a ditch; it can also be helpful, and it is linked to the harvest and to Samhain. The merrow is the Irish mermaid, recognisable by the small red cap, the cohuleen druith, that lets her return to the sea. If a man hides the cap, she must stay on land.

Then there is Fionn mac Cumhaill, leader of the Fianna, who gained his wisdom by accident. Set to watch the Salmon of Knowledge, the boy burned his thumb on the fish and sucked it, taking in a drop of its juice. From then on he could call up all the knowledge in the world by biting his thumb. It is a very Irish kind of heroism: not strength, but a fortunate mistake.

Where to find these stories today

The landscapes are the best guide. Newgrange and the Boyne Valley belong to the Tuatha Dé Danann, the Cooley Peninsula to the Táin, Lough Derravaragh to the swans, and the Hill of Uisneach and the Aran Islands to other layers of the tradition. The National Museum of Ireland in Dublin and the Ulster Museum in Belfast hold many of the archaeological objects behind the tales.

Frequently asked questions about Irish folklore

What is the difference between Irish mythology and Irish folklore?

Irish mythology is the older body of stories about gods and heroes, preserved in medieval manuscripts such as the Lebor Gabála Érenn and the Ulster Cycle. Irish folklore is the later, living tradition of fairy belief, local legends, charms and customs collected from ordinary people, especially in the nineteenth and twentieth centuries. The two overlap, but mythology is literary and heroic, while folklore is local and everyday.

Who is the most famous figure in Irish mythology?

Cú Chulainn is probably the best known, thanks to the Táin Bó Cúailnge. Fionn mac Cumhaill, the banshee, the Children of Lir and the Tuatha Dé Danann are also central, and each has its own cycle of stories.

Is the banshee evil?

No. In Irish tradition she is a warning, not a killer. She is tied to certain families, and her cry is heard before a death. She is closer to a mourning figure than to a monster.

Where can I see Irish mythology today?

Newgrange and the Boyne Valley, the Cooley Peninsula, Lough Derravaragh, the Hill of Uisneach and the Aran Islands all have landscapes tied to the stories. The National Museum of Ireland in Dublin and the Ulster Museum in Belfast hold many of the archaeological objects behind the tales.

More from the Mythical Mondays series

• Scottish folklore: kelpies, selkies and the Loch Ness Monster
• Norse mythology and Scandinavian folklore
• German folklore: myths, legends and folktales
• All Mythical Mondays posts

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