Fionn mac Cumhaill ( fin m?k-KOOL;[a]Old and Middle Irish: Find or Finnmac Cumail or Umaill, usually rendered as Finn McCool or Finn MacCool in English) was an Irish mythical hunter-warrior in Irish mythology, occurring also in the mythologies of Scotland and the Isle of Man. The stories of Fionn and his followers the Fianna, form the Fenian Cycle (an Fhiannaíocht), much of it narrated in the voice of Fionn's son, the poet Oisín.
In Old Irish, finn/find means "white, bright, lustrous; fair, light-hued (of complexion, hair, etc.); fair, handsome (often, but not necessarily, implying fairness of complexion); bright, blessed; in moral sense, fair, just, true". It is cognate with Proto-Irish VENDO- (found in names from Ogam inscriptions), Welsh gwyn, Cornish gwen, Breton gwenn, Continental Celtic and Brittonic *uindo- (a common element in personal and place names), and comes from the Proto-Celtic adjective masculine singular *windos (likely derived from the Proto-Indo-European root *weyd- "to know, to see").
Finn and his father Cumhall mac Trénmhoir ("son of Trénmór") stem from Leinster, rooted in the tribe of Uí Thairsig ("the Descendants of Tairsiu") There is mention of the Uí Thairsig in the Lebor Gabála Érenn as one of the three tribes descended from the Fir Bolg.
The mother was called Muirne Muincháem "of the Fair Neck" (or "of the Lovely Neck", or "Muiren smooth-neck"), the daughter or Tadg mac Nuadat (in Fotha Catha Chnucha) and granddaughter of Nuadat the druid serving Cathair Mór who was high-king at the time, though she is described as granddaughter of Núadu of the Tuatha Dé Danann according to another source (Acallam na Senórach). Cumhall served Conn Cétchathach "of the Hundre Battles" who was still a regional king at Cenandos (Kells, Co. Meath).
Cumhall abducted Muirne after her father refused him her hand, so Tadg appealed to the high king Conn, who outlawed Cumhall. The Battle of Cnucha was fought between Conn and Cumhall, and Cumhall was killed by Goll mac Morna, who took over leadership of the Fianna.
The Fianna were a band of warriors also known as a military order composed mainly of the members of two rival clans, "Clan Bascna" (to which Finn and Cumall belonged) and "Clan Morna" (where Goll mac Morna belonged), the Fenians were supposed to be devoted to the service of the High King and to the repelling of foreign invaders. After the fall of Cumall, Goll mac Morna replaced him as the leader of the Fianna, holding the position for 10 years.
Muirne was already pregnant; her father rejected her and ordered his people to burn her, but Conn would not allow it and put her under the protection of Fiacal mac Conchinn, whose wife, Bodhmall the druid, was Cumhall's sister. In Fiacal's house Muirne gave birth to a son, whom she called Deimne (; Irish pronunciation: [d?en?i]), literally "sureness" or "certainty", also a name that means a young male deer; several legends tell how he gained the name Fionn when his hair turned prematurely white.
Fionn and his brother Tulcha mac Cumhal were being hunted down by the Goll and siblings (the sons of Morna) and other men. Consequently, Finn was separated from his mother Muirne, and placed in the care of Bodhmall and the woman Liath Luachra ("Grey of Luachra"), and they brought him up in secret in the forest of Sliabh Bladma, teaching him the arts of war and hunting. After the age of six, Finn learned to hunt, but still had cause to flee from the sons of Morna.
As he grew older he entered the service - incognito - of a number of local kings, but each one, when he recognised Fionn as Cumhal's son, told him to leave, fearing they would be unable to protect him from his enemies.
Finn gains what commentators have called the "Thumb of Knowledge"[b] after eating a certain salmon, thought to be the Salmon of Wisdom. The account of this is given in The Boyhood Deeds of Fionn.
Young Fionn, still known by the boyhood Demne, met the poet Finn Éces (Finnegas), near the river Boyne and studied under him. Finnegas had spent seven years trying to catch the salmon that lived in Fec's Pool (Old Irish: Linn Féic) of the Boyne, for it was prophesied the poet would eat this salmon, and "nothing would remain unknown to him". Although this salmon is not specifically called the "Salmon of Knowledge", etc., in the text, it is presumed to be so, i.e., the salmon that fed on the nut[s] of knowledge at Segais. Eventually the poet caught it, and told the boy to cook it for him. While he was cooking it, Demne burned his thumb, and instinctively put his thumb in his mouth. This imbued him with the salmon's wisdom, and when Éces saw that he had gained wisdom, he gave the youngster the whole salmon to eat, and gave Demne the new name, Fionn.
In subsequent events in his life, Finn was able to call on ability of the "Thumb of Knowledge", and Fionn then knew how to gain revenge against Goll. In the Acallam na Sénorach, the ability is referred to as "The Tooth of Wisdom" or "Tooth of Knowledge" (Old Irish: dét fis).
One feat of Finn performed at 10 years of age according to the Acallam na Senórach was to slay Áillen (or [d]), the fire-breathing man of the Tuatha Dé Danaan, who had came to wreak destruction on the Irish capital of Tara every year on the festival of Samhain for the past 23 years, lulling the city's men to sleep with his music then burned down the city and its treasures.
When the King of Ireland asked what men would guard Tara against Áillen's invasion, Finn volunteered.[e] Finn obtained a special spear (the "Birga") from Fiacha mac Congha ("son of Conga"), which warded against the sleep-inducing music of Áillen's "dulcimer" (Old Irish: timpán)[f] when it was unsheathed and the bare steel blade was touched against the forehead or some other part of the body. This Fiacha used to be one of Cumall's men, but was now serving the high-king.
After Finn defeated Áillen and saved Tara, his heritage was recognised and he was given command of the Fianna: Goll stepped aside, and became a loyal follower of Fionn, although a dispute later broke out between the clans over the pig of Slanga.
Before Finn completed the feat of defeating the firebrand of the fairy mound and defending Tara, he is described as a ten-year-old "marauder and an outlaw". It is also stated elsewhere that when Finn grew up to become "capable of committing plunder on everyone who was an enemy", he went to his maternal grandfather Tadg to demand compensation (éric) for his father's death, on pain of single combat, and Tadg acceded by relinquishing the estate of Almu (the present-day Hill of Allen). Finn was also paid éric by Goll mac Morna.[g]
Fionn's sword was called "Mac an Luinn".
Fionn met his most famous wife, Sadhbh, when he was out hunting. She had been turned into a deer by a druid, Fear Doirich, whom she had refused to marry. Fionn's hounds, Bran and Sceólang, born of a human enchanted into the form of a hound, recognised her as human, and Fionn brought her home. She transformed back into a woman the moment she set foot on Fionn's land, as this was the one place she could regain her true form. She and Fionn married and she was soon pregnant. When Fionn was away defending his country, Fear Doirich (literally meaning Dark Man) returned and turned her back into a deer, whereupon she vanished. Fionn spent years searching for her, but to no avail. Bran and Sceólang, again hunting, found her son, Oisín, in the form of a fawn; he transformed into a child, and went on to be one of the greatest of the Fianna.
In The Pursuit of Diarmuid and Gráinne the High King Cormac mac Airt promises the aging Fionn his daughter Gráinne, but at the wedding feast Gráinne falls for one of the Fianna, Diarmuid Ua Duibhne, noted for his beauty. She forces him to run away with her and Fionn pursues them. The lovers are helped by the Fianna, and by Diarmuid's foster-father, the god Aengus. Eventually Fionn makes his peace with the couple. Years later, however, Fionn invites Diarmuid on a boar hunt, and Diarmuid is gored. Water drunk from Fionn's hands has the power of healing, but each time Fionn gathers water he lets it run through his fingers before he gets back to Diarmuid. His grandson Oscar shames Fionn, but when he finally returns with water it is too late; Diarmuid has died.
According to the most popular account of Fionn's death, he is not dead at all, rather, he sleeps in a cave, surrounded by the Fianna. One day he will awake and defend Ireland in the hour of her greatest need. In one account, it is said that he will arise when the Dord Fiann, the hunting horn of the Fianna, is sounded three times, and he will be as strong and as well as he ever was.
Many geographical features in Ireland are attributed to Fionn. Legend has it he built the Giant's Causeway as stepping-stones to Scotland, so as not to get his feet wet; he also once scooped up part of Ireland to fling it at a rival, but it missed and landed in the Irish Sea -- the clump became the Isle of Man and the pebble became Rockall, the void became Lough Neagh. In Ayrshire, Scotland a common myth is that Ailsa Craig, a small islet just off coast of the said county, is another rock thrown at the fleeing Benandonner. The islet being referred to as paddys' mile stone in Ayrshire. Fingal's Cave in Scotland is also named after him, and shares the feature of hexagonal basalt columns with the nearby Giant's Causeway in Northern Ireland.
In both Irish and Manx popular folklore, Fionn mac Cumhail (known as "Finn McCool" or "Finn MacCooill" respectively) is portrayed as a magical, benevolent giant. The most famous story attached to this version of Fionn tells of how one day, while making a pathway in the sea towards Scotland - The Giant's Causeway - Fionn is told that the giant Benandonner (or, in the Manx version, a buggane) is coming to fight him. Knowing he cannot withstand the colossal Benandonner, Fionn asks his wife Oona to help him. She dresses her husband as a baby, and he hides in a cradle; then she makes a batch of griddle-cakes, hiding griddle-irons in some. When Benandonner arrives, Oona tells him Fionn is out but will be back shortly. As Benandonner waits, he tries to intimidate Oona with his immense power, breaking rocks with his little finger. Oona then offers Benandonner a griddle-cake, but when he bites into the iron he chips his teeth. Oona scolds him for being weak (saying her husband eats such cakes easily), and feeds one without an iron to the 'baby', who eats it without trouble.
In the Irish version, Benandonner is so awed by the power of the baby's teeth and the size of the baby that, at Oona's prompting, he puts his fingers in Fionn's mouth to feel how sharp his teeth are. Fionn bites Benandonner's little finger, and scared of the prospect of meeting his father considering the baby's size, Benandonner runs back towards Scotland across the Causeway smashing the causeway so Fionn couldn't follow him.
The Manx Gaelic version contains a further tale of how Fionn and the buggane fought at Kirk Christ Rushen. One of Fionn's feet carved out the channel between the Calf of Man and Kitterland, the other carved out the channel between Kitterland and the Isle of Man, and the buggane's feet opened up Port Erin. The buggane injured Fionn, who fled over the sea (where the buggane could not follow), however, the buggane tore out one of his own teeth and struck Fionn as he ran away. The tooth fell into the sea, becoming the Chicken Rock, and Fionn cursed the tooth, explaining why it is a hazard to sailors.
In Newfoundland, and some parts of Nova Scotia, "Fingal's Rising" is spoken of in a distinct nationalistic sense. Made popular in songs and bars alike, to speak of "Fingle," as his name is pronounced in English versus "Fion MaCool" in Newfoundland Irish, is sometimes used as a stand-in for Newfoundland or its culture.
The hypothetical identification with Caittil Find (d. 856) a Norseman based in Munster, was even proposed by Heinrich Zimmer. This personage had a Norse name (Ketill) but also an Irish nickname Find "the Fair" or "the White", which might match Finn mac Cumhall. But Ketill's father must have had some Norse name also, certainly not Cumall, and the proposal was thus rejected by George Henderson.
Finn mac Cumhal was transformed into the character "Fingal" in James Macpherson's poem cycle Ossian (1760), which Macpherson claimed was translated out of discovered Ossianic poetry written in the Scottish Gaelic language. "Fingal", derived from the Gaelic Fionnghall, was possibly Macpherson's rendering Fionn's name as Fingal based on a misapprehension of the various forms of Fionn. His poems had widespread influence on writers, from the young Walter Scott to Goethe, but there was controversy from the outset about Macpherson's claims to have translated the works from ancient sources. The authenticity of the poems is now generally doubted, though they may have been based on fragments of Gaelic legend, 
Fionn mac Cumhaill features heavily in modern Irish literature. Most notably he makes several appearances in James Joyce's Finnegans Wake (1939), and some have posited that the title, taken from the street ballad "Finnegan's Wake", may also be a blend of "Finn again is awake," referring to his eventual awakening to defend Ireland.
Fionn also appears as a character in Flann O'Brien's comic novel, At Swim-Two-Birds (1939), in passages that parody the style of Irish myths. Morgan Llywelyn's book Finn Mac Cool (1994) tells of Fionn's rise to leader of the Fianna and the love stories that ensue in his life. That character is celebrated in "The Legend of Finn MacCumhail", a song by the Boston-based band Dropkick Murphys featured on their album Sing Loud Sing Proud!.
Glencoe: The Story of the Massacre by John Prebble (Secker & Warburg, 1966), has an account of a legendary battle between Fionn mac Cumhaill, who supposedly lived for a time in Glencoe (in Scotland), and a Viking host in forty longships which sailed up the narrows by Ballachulish into Loch Leven. The Norsemen were defeated by the Feinn of the valley of Glencoe, and their chief Earragan was slain by Goll MacMorna.
Finn McCool is a character in Terry Pratchett's and Steve Baxter's The Long War.
The adventures of Fion Mac Cumhail after death is explored by the novella "The Final Fighting of Fion Mac Cumhail" by Randall Garrett (Fantasy and Science Fiction - September 1975).
Finn's early childhood and education is explored in 'Tis Himself: The Tale of Finn MacCool by Maggie Brace.
Other stories featuring Fionn Mac Cumhail are two of three of the stories in The Corliss Chronicles the story of Prudence Corliss. In the stories he is featured in The Wraith of Bedlam and The Silver Wheel. He is a close confidant to Prudence and allies himself with her to defeat the evil fictional king Tarcarrius.
In the 1999 Irish dance show Dancing on Dangerous Ground, conceived and choreographed by former Riverdance leads, Jean Butler and Colin Dunne, Tony Kemp portrayed Fionn in a modernised version of The Pursuit of Diarmuid and Gráinne. In this, Diarmuid, played by Colin Dunne, dies at the hands of the Fianna after he and Gráinne, played by Jean Butler, run away together into the forests of Ireland, immediately after Fionn and Gráinne's wedding. When she sees Diarmuid's body, Gráinne dies of a broken heart.
In 2010, Washington DC's Dizzie Miss Lizzie's Roadside Revue debuted their rock musical Finn McCool at the Capitol Fringe Festival. The show retells the legend of Fionn mac Cumhaill through punk-inspired rock, and was performed at the Woolly Mammoth Theater in March 2011.
Played by Daniel Quirke on the Edenderry Barge in 2002, with an Emmy Award nominated performance (Art by: Maeve Quinn).