The Fenian Cycle (Irish: an Fhiannaíocht) is a body of prose and verse centering on the exploits of the mythical hero Fionn mac Cumhaill and his warriors the Fianna. It is one of the four major cycles of Irish mythology along with the Mythological Cycle, the Ulster Cycle, and the Historical Cycle. Put in chronological order, the Fenian cycle is the third cycle, between the Ulster and Historical cycles. The cycle also contains stories about other Fianna members, including Caílte, Diarmuid, Oisín's son Oscar, and Fionn's enemy, Goll mac Morna.

It is also known as the Fianna Cycle, Fionn Cycle, Finn Cycle and Ossianic Cycle.

Plot summary:

Cormac mac Art, the High King of Ireland formed the Fianna, a coalition of clans, for the protection of the kingdom. The Fianna was dominated by Clan Bascna, led by Cumhal, and Clan Morna, led by Goll, with Liath Luachra, the treasurer. After the Battle of Knock, Cumhal is killed by the Morna, and Clan Bascna's treasure bag is stolen. Cumhal's wife, Muirne, runs away and has a son, Demna, who is cared for by two warrior women, Liath and the druidess Bodhmall. Muirne marries the king of Kerry.

Fionn's rise:

Demna got the name Fionn because of his fair hair, and as soon as he came of age he set off for revenge. He kills Liath Luachra, and retrieves the treasure bag, which he then gives to the survivors of the Battle of Knock. While studying with the poet Finn Eces, Fionn accidentally eats the Salmon of Wisdom, and is admitted to the court of the High King at Tara, after passing three strenuous tests. After he was admitted, Fionn became the leader of Clan Bascna.

Fionn and Aillén:

Every Samhain, the goblin Aillén mac Midgna, or Aillén the Burner, would terrorize Tara, playing music on his harp that left every warrior helpless. Using a magic spear that rendered him immune to the music, Fionn killed the goblin. As a reward, Fionn was made the leader of the Fianna, replacing Goll, who had to swear fealty to him.

Fionn and Sadbh:

Fionn was hunting a fawn, but when he caught it, his hounds Bran and Sceolang wouldn't let him kill it, and that night it turned into a beautiful woman, Sadbh, who had been transformed into a fawn by the druid Fer Doirich. The spell had been broken by the Dun of Allen, Fionn's base, where, as long as she remained within she was protected by the spell. They were married. Some while later, Fionn went out to repulse some invaders and Sadbh stayed in the Dun. Fer Doirich impersonated Fionn, tempting Sadbh out of the Dun, whereupon she immediately became a fawn again. Fionn searched for her, but all he found was a boy, who he named Oisín, who had been raised by a fawn. Oisín became famous as a bard, but Sadbh was never seen again.

The Battle of Gabhra:

Between the birth of Oisin and the Battle of Gabhra is the rest of the cycle, which is very long and becomes too complicated for a short summary. Eventually the High King Cormac, dies and his son Cairbre Lifechair wants to destroy the Fianna, because he does not like paying the taxes for protection that the Fianna demanded, so he raises an army with other dissatisfied chiefs and provokes the war by killing Fionn's servant. Goll sides with the king against Clan Bascna at the battle. Some stories say five warriors murdered Fionn at the battle, while others say he died in the battle of the Ford of Brea, killed by Aichlech Mac Dubdrenn. In any case, only twenty warriors survive the battle, including Oisín and Caílte.

Associated works:

In the introduction to his Fianaigecht, Kuno Meyer listed the relevant poems and prose texts between the seventh and fourteenth centuries and further examples can be adduced for later ages:

Seventh century:

poem attributed to Senchán Torpéist, along with Finn's pedigree, in a genealogical tract of the Cocangab Már 'The Great Compilation' (Rawlinson B 502 and the Book of Leinster).

Late eighth or early ninth century:
"The Quarrel between Finn and Oisin"
"Finn and the Man in the Tree"
Reicne Fothaid Canainne

Ninth century:

"How Finn obtained knowledge and the Death of the Fairy Culdub"
Bruiden Âtha Í
"Find and the jester Lomnae"
Cormac's Glossary, entry for rincne: Finn as member of Lugaid Mac Con's 'fian,
"Ailill Aulom, Mac Con and Find ua Báiscne"
Poem ascribed to Maelmuru Othna in the dindsenchas of Áth Liac Find, where Finn is called 'mac Umaill'.
Poem ascribed to Flannacán mac Cellaig, king of Bregia, in the Yellow Book of Lecan (125a), on Finn's death on Wednesday.
Story according to which Mongán was Finn.

Tenth century:

Triads of Ireland: anecdote about Finn and the boar of Druimm Leithe.
Poem ascribed to Cináed úa Hartacáin on the cemetery of the Brug on the Boyne: on Finns death.
Two poems on the dindsenchas of Almu.
Poem on the dindsenchas of Fornocht
Poem on the dindsenchas of Ráith Chnámrossa
Poem ascribed to Fergus Fínbél on the dindsenchas of Tipra Sengarmna
"Finn and Gráinne"
"Finn and the Phantoms" (prose)
Poem on Leinstermen and their expeditions against the Leth Cuinn
Poems on winter and summer
Poem ascribed to Erard mac Coisse
Tochmarc Ailbe
Aithed Gráinne ingine Corbmaic la Díarmait húa mDuibni (lost)
Úath Beinne Étair
Úath Dercce Ferna or Echtra Fhind i nDerc Ferna (lost)
"The Death of Finn" (fragment).

Eleventh century:

Poem by Cúán úa Lothcháin on the dindsenchas of Carn Furbaidi and Slíab Uillenn
Treatise on Irish metrics, on Finn as one of twelve famous poets.
Fotha Catha Cnucha (Lebor na hUidre)
Poem "Finn and the Phantoms"
Poem on the birth of Oisín (two quatrains in LL)
Notes on Félire Óengusso
Text on Irish Ordeals
Poem by Gilla Coemain, "Annálad anall uile" (first line)
Annals of Tigernach, AD 283, on Finn's death.

Twelfth century:

Tesmolta Cormaic ui Chuinn ocus Aided Finn meic Chumail
Prose Dindsenchas
Poem in LL on a hound from Irúaith
Poem on the dindsenchas of Snám Dá Én
Poem attributed to Finn on the dindsenchas of Róiriu i nHúib Failge
Macgnímartha Finn, "The Boyhood Deeds of Finn"
Poem attributed to Oisín
Poem by Gilla in Chomdéd
Poem by Gilla Modutu
Bannsenchas Érenn
Story of Mac Lesc mac Ladáin and Finn
Poem attributed to Finn on the dindsenchas of Mag Dá Géise
Poem ascribed to Oscur on the battle of Gabair Aichle
Poem attributed to Cáilte, written in the so-called bérla na filed 'the poets' language'.
Poem attributed to Oisín on the conversion of the fiana
Poem attributed to Cáilte on the dindsenchas of Tonn Clidna.
Áirem muintire Finn
Poem attributed to Finn on the deeds of Goll mac Mornai Glinne Garad.

Thirteenth and fourteenth centuries:

Acallam na Senórach
"The Chase of Slieve na mBan"

Late Fifteenth and early Sixteenth centuries:
Cath Finntrágha ("The Battle of Ventry")
"Book of the Dean of Lismore" (Scottish)

Seventeenth century:

Duanaire Finn, book of miscellaneous poems written by Aodh Ó Dochartaigh.
Tóraigheacht Dhiarmada agus Ghráinne, "The Pursuit of Diarmuid and Grainne"

Eighteenth century:

Collections made in the Scottish Highlands by Alexander Pope, Donald MacNicol, Jerome Stone, James McLagan, and others

Nineteenth century:

Further collections in Scotland and Ireland

Twentieth century:

Tape recordings collected in the Scottish Highlands by Hamish Henderson, John Lorne Campbell and others, of sung performances as well as prose tales.