One night Eoghan went to the house of Dil of the Crecraighe tribe, before going to the battle of Magh Mucruimbe. Dil then lived at Carn Fhearadhaig in the territory of the Northern Deis. This Dil then had a marriageable beautiful daughter called Muncha. While they were drinking Dil, the Druid, asked Eoghan if he had a family. No, said Eoghan. "Sleep with my daughter tonight," said the druid "and you shall have a wonderful child."" Eoghan agreed with this and Dil went to his daughter and said, "Cohabit with Eoghan tonight and there shall be conceived a son and he shall be a king and his family and race shall be a royal one afterwards and Eoghan shall be slain in the forthcoming battle of Magh Muchraime.
Muncha lay with Eoghan that night, at the druid's directive. Eoghan went off in the morning along with his kinsmen to join forces with Art son of Conn (from Tara) and they went to the battle of Magh Muchruime. Afterwards the druid and his daughter Muncha went to Western Magh Femhin, for there was Eoghan's residence at Knockgraffon. When the time came for the child to be born, the druid said, "Daughter, if it is today that you shall bear the child, he shall be a druid; but if he is not born until tomorrow, the child shall be king and his descendants shall be a royal race."
Muncha said: "My son shall not be born until tomorrow so that he shall be king. The daughter of Dil's then goes to the River Suir, to Ath Hisil on the Suir. There was a great flagstone in the middle of the ford there - she lay flat on the stone until daybreak on the following day. It is time now, O daughter - said her father, "to bear the child." The wonderful talented youth was then born, in the middle of the flagstone that is Fiacha Muilleathan - father of all the eoghanachta (tribe of Owen). Noble was the youth then born - Fiacha Fer da Liach i.e., Fiacha the Man of two Sorrows; his father was slain the day after his conception, his mother on the day of his birth.
Eventually Fiacha Muilleathan, son of Eoghan Mor, assumed the kingship of the two Munsters and during his reign Cormac Ua Cuind, king of Ireland, came (from Tara) with a hosting into Munster, demanding tribute from the two provinces of Munster. Cormac besieged the Munstermen at Druim Damhaire (Knockloag); this king weilded [sic] great power, both by the vastness of his army and the power of his druids. Cormac had British druids weaving their spells against the Munstermen, so that by necromancy they had dried up all the wells and rivers of Munster, so that the people and their lands were in danger of death from the want of water.
Then Fiacha Muilleathan sent for Mogh Ruith son of Fergus, the best druid to be found in Ireland. Mogh Ruith then lived in Oilen Dairbhre (Valentia Island) in his old age, blind and decrepit, as he had outlived nineteen kings of Ireland:- from the time of Roth mac Rioghuill (the druid who had trained Mogh Ruith in sorcery) to the time of Cairbre Lifechair son of Cormac mac Airt. Mogh Ruith then came to meet Fiacha Muilleathan and the Munster nobles and they complained about what the druids of Leath Cuinn (Northern half of Ireland) had done to them. he undertook to oppose their magic spells, and he chose the territory of Fir Mhwige (Fermoy) as his reward. Mogh Ruith then overcame the druidery of Cormac and they defeated Cormac's forces routing them from Knockling to Tara with a great massacre. Fiacha Muilleathan the Munster king did not leave Leath Cuind until he got hostages and homage from Cormac mac Airt; as the poet Feidhlime mac Crimithann wrote:-
Good was the king Fiacha Muilleathan
A great territory the Half over which he ruled
He brought hostages from Tara the Strong
To Rathfuim to Rath Naoi
Though he was great; Cormac Ua Cuinn
He bowed to the king of Tir Duinn (Munster).226

http://www.gendex.com/users/jast/D0014/G0000017.html#I6954
Fiachu Mullethan (K of Munster)
Reference: 6954
Father: Eogan Mor
Family 1:
1.Ailill Flann-Bec
Notes Byrne's "Irish Kings and High Kings". Few modern scholars consider any of the genealogy before this point historical.

Conla was educated at the Court of Cormac at Tara. He suffered from leprosy. Cormac advised Conla that he would never be cured until he washed his sores in the blood of a king. At this time Conla had a rival--the King of Munster--Fiachadh Muilleathan, who had successfully resisted Cormac's demand for tribute, and even obtained hostages from Cormac. Conla left Tara, and went to visit this king of Munster. He was received with great favour at Cnoc Rathfuin (Knock Raffan) in Tipperary where the king dwelt. One day the king went to bathe in the River Suir, and Conla was allowed to carry his spear. The king plunged into Aith Uisiol to bathe; after a time he swam towards the bank where Conla was standing. Conla drove the spear through the king's body. The attendants hastened to take revenge on Conla, but the king ordered them to spare his life. The king died.293