Fionn mac Cumaill

Fionn mac Cumaill Comes to the Aid of the Fianna

Fionn mac Cumaill anglicised to Finn McCool in the Romantic Period of the 1800s) was a mythical hunter-warrior of 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 or Fiannaidheacht, much of it purported to be narrated by Fionn's son, the poet Oisín.

Fionn or Finn is actually a nickname meaning "fair" (in reference to hair and/or skin colour), "white", or "bright". His childhood name was Deimne "Sureness, Certainty", and several legends tell how he gained the nickname when his hair turned prematurely white. The name "Fionn" is related to the Welsh name Gwyn, as in the mythological figure Gwyn ap Nudd, and to the continental/Roman British Celtic Vindos, also a 'nickname' for a god such as Belenos.

The 19th century Irish revolutionary organisation known as the Fenian Brotherhood took its name from these legends. The Scottish name Fingal comes from a retelling of these legends in epic form by the eighteenth century poet James Macpherson.

Contemporary Scottish poet Marie Marshall has written a semi-serious ballad in parody of 19c neo-medievalism "How Finn McCool became Lord of Tara". It deals with how Finn saved the noble house of Tara from the evil spell of Allan-of-the-Harp, an elf-king with a hatred of human prosperity. A sample passage runs thus:

For three and twenty years the hall
Of Tara’s King was razed and burned
On Harvest Eve. But none recall
Who from that eldritch sleep returned
The harping of the evil elf –
In mystery was Tara cloaked –
Until young Finn McCool himself
The right of rest and board invoked
One summer’s end, and joined their feast.
A modest boy of humble mien,
He sat the lowest, ate the least,
Observed the merrymaking scene.
At midnight sharp came Allan in
And shrouded all with slumber foul
Except the youthful paladin,
Who hid a spear beneath his cowl
And pressed the blade against his cheek.
Then Allan stalked around the room
And wrathfully began to speak.
“This is brave Goll McMorna’s doom,
That once a year shall Tara fall
And fire her rising towers destroy.
And thus I curse you, one and all!”
At which, up sprang the noble boy…