Emerald Isle

Mogh Ruith

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Irish and Celtic myths and legends, Irish folklore and Irish fairy tales from the Historical Cycle

An ancient druid of terrible power, summoned back to do battle with King Cormac

Through many an ancient legend and tale rings the name of the fierce and powerful druid called Mogh Ruith, meaning “slave of the wheel”. Older legends make him out to be the king of the Fir Bolg, or a druid gifted with many lives by the fairies, or that the name was but a title passed down through generations.

Some say he had one eye, and some say none, having lost the first becoming a mound of snow in the high mountains, and the second while trying to stop the sun in its course. There are even rumours that his tale became that of Merlin over the course of ages!

His powers were many and fearful – the summoning of dragons, which people of old called fire-eels, the raising of storms and the unbinding of wells that their water might flow freely again, turning enemies to stone and even raining blood from the sky! He could grow to enormous size, and his breath caused storms.

He wore a hornless bull-hide and a bird mask, the encennach, and his roth ramach or rowing-wheel made from two pillars of stone which he used to fly through the sky as lightning flickered around him. When he rode it, night became as bright as day, and he carried a star-shimmering black shield with a silver rim.

He it was who spent his first seven years of druidic training in Sí Cairn Breachnatan under the direction of the druidess Banbhuana, the daughter of Deargdhualach. Neither inside nor outside of the sí dwelling place nor in any other place was to be found a form of magic which he had not practised, and among the people of Ireland, Mogh Ruith was the only one who ever learned his magic arts within a sí, or fairy mound.

Stories about Mogh Ruith appear throughout Irish history. In the middle ages, it was written that he was a companion of Simon Magus and was even the executioner of John the Baptist, bringing a curse on the pagan tribes of Ireland. In Lebor Gabála Érenn he is said to have died in the reign of Conmael, three thousand years ago. Some of the poets say he lived through the reign of nineteen kings.

His father was Cethern and his daughter was Tlachtga, a mighty druidess, who gave her name to what became known as the Hill of Ward, and first lit the Samhain fires.

He made his home on Dairbre Island off county Kerry, at least until he was called upon to do battle with Cormac Mac Airt the wolfborn! For Cormac wanted to be High King of all Ireland, and so he intended to levy taxes on the men of Munster in the South, a duty they were unwilling to fulfil.

So Cormac marched his armies to Druim Damhgaire and his druids dried up all the water in the land, causing much terror, until King Fiacha Muillethan of southern Munster called upon the mystical powers of  Mogh Ruith to answer, although the druid's price was steep. When he met the King's men he told them what he needed in order to help them:

“Not difficult to say", said he, “100 milk cows with shining milk-white hides, 100 well-fattened pigs, 100 working oxen, 100 racehorses, 50 splendid cloaks of criss-cross weave, a daughter of the best or second best man in the province to provide me with children, so that just as I am of noble birth from my fathers, so I desire that my children be noble also by reason of their mothers, so that it may be by comparison with my family that the nobility of every free ógthiarna be judged!”

And he went on “The first place among the cavalry of the king of Munster so that my representative will always have the status of a provincial king and that these conditions shall never be infringed but that everything promised to me will be fulfilled. Moreover, a man of counsel and wisdom will be appointed by me as advisor to the king of Munster and if the king follows his counsel fortune will smile on him. This counsellor, however, may be demoted or put to death according to the king's judgment should he dare to reveal any of the royal secrets. For my descendants also, a right to convene meetings and three men in attendance on the king and one at his right hand.”

But he wasn't done yet!

“I furthermore demand, that the territory of my choice in Munster be given me – as large as my servants can encircle in one day. The king of Munster never to exercise authority or representation over this area; not to demand a hostage from my representative but only that his horsewhip be left behind or to close the hand of the king of Munster around his ankle. I do not acknowledge my race as being guilty of weakness or cowardice and I recommend them to join the company of the king of Munster in battle and skirmish as a reminder and acknowledgement of mutual debts!”

Well he got what he asked for and straight away thrust a spear into the earth, making a crack from which water spouted in great volumes. He breathed out a cloud of darkness which dampened the powers of Cormac's druids, descending upon their camp, and three of them he turned to stone - these stones are know as Leaca Roighne today.  

Cormac's druidesses had transformed to sheep ringed with fire, so he brought up fierce hounds of hell to pursue them and hunt them across the land, until they fell into a deep crevice and were consumed. More fires were raised from rowan wood and sent to char Cormac's armies, and a dragon of the dark oceans he summoned in order to defeat Cormac's champion, and he caused a rain of blood to dismay the forces arrayed before him.

After that, Cormac gave it up and a lasting peace was formed between the north and south. Seeing the devastation which had been unleashed, the men of Munster questioned Mogh Ruith about the number of casualties on both sides – north and south – and which side had suffered the most. Mogh Ruith gave a clear description of the situation in the following lay which he recited aloud:

The lawless ones killed
480 brave warriors
of the Men of Munster,
according to my calculations.
Five druids practised sorcery
against Leath Mhogha of the large assemblies;
this was the number killed, an impressive deed.
I formed three hounds
to destroy the brave sheep.
I formed an underwater sea-eel
to destroy Colpa and Lorga.
I turned the fires northwards
to Leath Choinn of the hard swords.
I left only the strength of a woman in labour
to the descendants of Conn Céadchathaigh in the east.

Warlike Munster defeated Conn.
Once their Aos Dána (Men of Art) had failed
Cormac's army fell into distress.
Four hundred lords and kings
of Cormac's band are calculated to have been killed
on the way to Formhaol. It was an injury beyond repair
for the descendants of Conn Céadchathaigh.
Exactly 400 horse-boys
belonging to Cormac's army were killed on the road

between Formhaol and Roighne.
Crotha, Céacht, Cith Rua from the plain
druids of the race of Conn Céadchathaigh
at Má Roighne of the red rocks
I turned them into solid stones.
These stones will commemorate the deed,
they will remain there for ever,
a cause of shame for Leath Choinn;
they will be known as Leaca Roighne.
There were five groups of seven men each there,
having only five names.
Everybody was forced to a retreat
except for three.
There were seven men in each of the groups belonging to Céacht, Crotha,
Ceathach, Cith Mhór
and Cith Rua. Their feats were brilliant
as was their composition of druidic spells.

at Áth an tSlua,
north of Má Roighne,
a group of seven twenties was killed –
that I do not conceal.
Two twenties and two hundred
fell from that ford eastwards that is not lie,
on every path that Leath Choinn took.
They were not given protection in Liathruim (Tara).
There were 1048 men killed

this was the destruction wrought on Leath Choinn
by the grandson of Oileall Ólom.
From pleasant Druim Dámhgháire
to the great highway of Slí Mhíluachra.
A great and bloody deed took place
in one day.
It is the greatest march
that a warrior ever undertook among brilliant feats of valour.
From Ceann Chláire it was a splendid journey
northwards to Gleann Rí Righe.
Fiacha of the numerous companies
and Mogh Corb of the red sword
decided that they would not be fully satisfied
until Cormac became their hostage.

Tales tell that the territory Mogh Ruith received for his descendants was Fir Maige Féne, known today as Fermoy. It was by this and other signs that Cormac Mac Airt learned well the folly of trusting in the old spirits of Ireland and the pagans, and came in the end to embrace the light of the Lord.


More Tales from the Historical Cycle

Irish fairy tales, Irish folklore