As to Conn's other brother, namely, Fiachaidh Suighdhe, he got land near Tara, namely, the Deise Teamhrach; and he did not become king of Ireland.
Now he had three sons, namely, Rossa and Aonghus, called Aonghus Gaoibuaibhtheach, and Eoghan, the third son. But Aonghus Gaoibuaibhtheach surpassed his contemporaries in valour. And Cormac at that time was at enmity with a powerful personage, and no one protected him from Cormac but Aonghus Gaoibuaibhtheach; and the king gave Aonghus to him as a security. Aonghus took this nobleman under his protection. But after this, Ceallach son of Cormac took this nobleman prisoner in violation of the security of Aonghus, and took out his eyes without the king's permission. When Aonghus Gaoibuaibhtheach heard this, he proceeded to Tara, accompanied by a numerous host, and slew Ceallach by a cast of his spear, as he stood behind king Cormac in the court, and wounded the king himself in the eye, leaving him with only one eye. Cormac assembled a large host and banished Aonghus and his kinsmen.
These descendants of Fiachaidh Suighdhe involved Cormac in much fighting. However, Cormac drove them into Leinster, and they remained there a year; and thence they went to Osruighe, and thence they came to Oilill Olom, whose wife, Sadhbh daughter of Conn, was their kinswoman. Oilill Olom gave them the Deise in Munster, for their native territory was the Deise Teamhrach, before they were banished by Cormac.
These three sons of Fiachaidh Suighdhe divided that territory between them into three parts; and they are called the descendants of Oilill Earann, and the Earna. However, they are not the Earna, but the descendants of Conaire son of Mogh Lamha it is these that were styled the Earna. It is Corc Duibhne son of Cairbre Musc who was chief over the descendants of Fiachaidh Suighdhe who came to Munster; and it was these descendants that were called the Deise; and Aonghus son of Eochaidh Fionn son of Feidhlimidh Reachtmhar was their leader when coming to Munster, and with him were the three sons of Fiachaidh Suighdhe, namely, Rossa, Eoghan, and Aonghus. About that time Cairbre Musc had acquired great power in Munster; and in his time adversity and crop-failure had come upon Munster. Nor was this strange, for it was by incest and crime that he became father of Corc by Duibhfhionn, his own sister; for they were the children of Conaire son of Mogh Lamha and of Saruit daughter of Conn Ceadchathach. When the Munster nobles observed the adversity that came with Cairbre's reign, they asked him what had deprived the country of its produce and its prosperity. Cairbre replied that it was because he had committed incest with his sister Duibhfhionn, and she had borne him two sons, to wit Corc and Cormac; and when the Munster nobles heard this, they demanded the sons, in order to destroy them -- to burn them, and let their ashes go with the stream. "Act in that way towards Cormac," said Dinneach the Druid; "but do not kill Corc, but let him be given to me, that I may take him out of Ireland." This was granted to him; and he took him with him to sea, to Inis Baoi; and he found a house on the island in which was a crone called Baoi; and the druid placed Corc under her protection, and he remained with her for a year, and at the end of the year the druid took Corc and placed him under the protection of Saruit daughter of Conn, who was grandmother to the child, both on his father's and mother's side.
As to the Deise, they inquired of their filés whether they were fated to have rest or dwelling in Munster; and the filés told them in reply to stay in the country, and that the wife of Criomhthann son of Eanna Cinnsealach, king of Leinster, whose name was Congain, was pregnant, and that it was a daughter she would bring forth, and that they should ask the daughter in fosterage, and give a fee in order to obtain her. After this the daughter was born; and she was fostered by the Deise. The daughter's name was Eithne Uathach, and she was fed by the Deise on the flesh of infants that she might grow up the more quickly; for a certain druid had foretold that they would get territory from the man whose wife she would be. And when she was of age to wed, she was married to Aonghus son of Natfraoch, king of Munster. And Aonghus gave them, in consideration of getting her to wife, Magh Feimhean, that is, Trian Chluana Meala, and the Trian Meadhonach after the expulsion of the Osruighigh from these territories. And a long time after this Aonghus and Eithne were slain by the Leinstermen in the Battle of Ceall Osnadh, four miles east of Leithghlinn.
These descendants of Fiachaidh Suighdhe, who are called the Deise, possessed only the district known as Deise Dheisceirt, that is, from the Siuir southwards to the sea, and from Lios Mor to Ceann Criadain, up to the time when Eithne Uathach was married to Aonghus son of Natfraoch, king of Munster. For it was about that time that Aonghus gave them Deise Thuaisceirt, that is, from the same Siuir to Corca Athrach, which is called the Plain of Cashel. And O Faolain, who came from that stock, was king of Deise Thuaisceirt; and the place in which his residence was situated was on the brink of the Siuir to the west of Inis Leamhnachta; and Dun Ui Fhaolain is the name it is called to-day. Another kinsman of his occupied Deise Dheisceirt, and he was called O Bric; and he had his stronghold beside the sea, in the south, in the place which is now called Oilean Ui Bhric. And the Deise were divided thus between these two races until the race of O Bric became extinct; and O Faolain obtained the chieftainship of the two territories, and held it for a long period afterwards, until the race of Eibhear took Deise Thuaisceirt from him; and so he possessed only Deise Dheisceirt on the coming of the Foreigners to Ireland.
Understand that it was Aonghus Osruighe and his followers that obtained sway over Magh Feimhean, which is called Deise Thuaisceirt, and that it was this sept of Fiachaidh Suighdhe who expelled Aonghus Osruighe and his followers from Magh Feimhean; and from the defeat they inflicted on Aonghus are named Baile Orluidhe, and Mullach Inneona in Magh Feimhean at this day; Baile Orluidhe from the urlaidhe or long hair of the warriors in the battle, and Mullach Inneona from the Osruighigh having been driven from it to Leinster against their will.
About this time Cormac son of Art, king of Ireland, felt a scarcity of meat, having spent the rents of the provinces because of the extent of his household staff; and he took counsel with his high-steward, how he could obtain supplies for his staff until the time of his rent-taking; and the steward advised him to assemble a large host, and go into Munster to levy the head rent of the king of Ireland. "For they only pay thee," said he, "the rent of one province, while there are two provinces in Munster, and each of these provinces should pay the rent of a province to the king of Ireland." Cormac acted on that advice, and sent envoys to Fiachaidh Muilleathan, who was then king of Munster, demanding from him the rent of the second province. Fiachaidh answered the envoys, and said that he would not pay a higher rent to Cormac than was paid to the kings who preceded him. And when this answer reached Cormac, he assembled a large host, and marched with them, and halted not till he reached Druim Damhghaire in Munster, which place is now called Cnoc Luinge. And there he fixed his tent or camp; and Fiachaidh Muilleathan, king of Munster, came on the other side against him front to front.
At that time Cormac was thus circumstanced: he had druids from Alba with him there, who practised much magic against the king of Munster and his followers, and in particular, not a drop of water was left near the camp of the king of Munster, and so people and cattle were on the point of death through want of water, and the king of Munster was obliged to send for Mogh Ruith, a druid, who was in Ciarraidhe Luachra; and this Mogh Ruith lived in the time of nineteen kings, as the poet says in this stanza:
The reign of nineteen successive kings
Was the life of Mogh Ruith with much fighting,
From Roth son of Rioghall, great the fame,
To Cairbre Lithfeachair the strong.
And when Mogh Ruith came, the king was obliged to give him two cantreds of Feara Muighe, which are called the country of the Roistigh and the country of the Condunaigh. And thereupon Mogh Ruith removed the barrier that had been put to the water withholding it, and at the same time threw up into the air a magic spear which he had, and in the place in which the spear fell there burst forth a well of spring water which relieved the men of Munster from the thirst that afflicted them; and hereupon the king of Munster with his host made a sudden onset on Cormac and his followers, and expelled them from Munster, without their having fought a battle or carried off a spoil. And they pursued them to Osruighe, so that Cormac was forced to give pledges and securities that he would send hostages from Tara to Raith Naoi, which is called Cnoc Rathfonn, to Fiachaidh Muilleathan, as a guarantee that he would make compensation for all the injury he had done to Munster in that expedition; and as a declaration of this, the poet composed this stanza:
Fiachaidh Muilleathan, good the king,
From the land of Aibhle in Leitre Craoi,
Hostages from great Tara were sent him
To bright Rathfonn to Raith Naoi.
This Fiachaidh had two sons, to wit, Oilill Flann Mor and Oilill Flann Beag. Oilill Flann Mor had no issue, and it is from Oilill Flann Beag that all who survive of the race of Fiachaidh Muilleathan are descended. And hence the poet indites this stanza:
The sons of great Fiachaidh Muilleathan
Were Oilill Flann Mor of the mead-drinking,
And Oilill Flann Beag of the hosts;
His progeny are great in Munster.
Now, as Oilill Flann Mor was without issue, he adopted his brother Oilill Flann Beag as a son, and left him his personal effects and his inheritance on condition that he and his descendants should place his name in the genealogy between his own name and that of Fiachaidh Muilleathan; and so it is in the Psalter of Cashel, and in other ancient books. It is not, however, to be inferred from them that Oilill Flann Mor was the father of Oilill Flann Beag. But the reason why the chroniclers used to put the name of Oilill Flann Mor in the genealogical tree of Fiachaidh Muilleathan was to commemorate the compact that existed between himself and Oilill Flann Beag, as we have said above. Fiachaidh Muilleathan was treacherously slain by Connla Clamh son of Tadhg, son of Cian, ancestor of the siol Cearbhaill and of the siol Meachair at Ath Uiseal, which is called Ath Aiseal on the Siuir at the present time. And the reason why he did that deed of treachery was that when Connla was a youth with Cormac son of Art, learning manners and accomplishments, leprosy or mange came upon him, and no medical treatment whatever availed him. Cormac told him on that occasion that there was no cure destined for him, until he should wash himself in the blood of a king, and that were he to do that he would be healed of his mange. Soon after this Connla took his leave of Cormac, and went into Munster to visit his kinsman, Fiachaidh Muilleathan, who was then king of Munster. And at that time Fiachaidh Muilleathan resided at Raith Rathfainne, which is now called Cnoc Rathfonn, with his foster-mother, whose name was Rathfonn; and when Connla came into his presence, he bade him welcome.
Now, on a certain day soon after this, Fiachaidh went out beside the Siuir with all his household, attended by Connla, who carried his spear; and he went as far as Ath Aiseal, and proceeded to swim in the stream; and Connla bethought him of Cormac's instructions. And thereupon he went to the verge of the bank, and stabbed Fiachaidh with his spear as he swam, and thus slew him. Fiachaidh, however, before he died, protected Connla, and forbade his household to slay him. And he died immediately after that. And it was in this way the life of Fiachaidh Muilleathan ended.