Geoffrey Keating took the Irish saga stories as historical facts. Contemporary historians view the saga stories as a few "skeletal" tenth century historical facts mixed together with a very large dose of 12th Century political propaganda and a large number of entertaining fictional stories. This genre of historical fiction was normal for its time and is still being written today. The many stories and movies about King Arthur are an example.
The following are excerpts from The History of Ireland, by Geoffrey Keating, D.D., Volume III, containing the second book of the History, edited with translation and notes by Rev. Patrick S. Dineen, M.A., London: Published for the Irish Texts Society by David Nutt. 57-58 Long Acre (1908:223-233).
Comments by Kevin L. Callahan are enclosed in [brackets].
[The Inauguration of Ceallachan as the King of Munster]
XXII.
"It was in the reign of Donnchach son of Flann Sionna, king of Ireland [an Ui Niall from Ulster and an enemy who participated in the unsucessful Viking attempt to have Ceallachan killed], that the following events took place. For it was in the beginning of his reign that Ceallachan, son of Buadhachan, who is called Ceallachan of Cashel held the sovereignty of the two provinces of Munster ten years. Now Cinneide [Kennedy, father of Brian Boru and a rival], son of Lorcan, came to Gleannamhain to an assembly of the nobles of Munster before Ceallachan was inaugurated, and Cinneide sought to come between Ceallachan and the sovereignty of Munster. But Ceallans [sic. probably a printers typo for Ceallachan] mother came from Cashel, for it was there she dwelt with her tutor, Patricks comhorba [successor of Saint Patrick], and coming into the assembly she asked Cinneide to remember the agreement come to between Fiachaidh Muilleathan and Cormac Cas [second century kings of southern Ireland ] that the descendants of both should alternately inherit Munster [the southwestern province of Ireland], and this is expressed by this stanza on the womans words
Remember, 0 pleasant Cinneide.
The agreement of Fiachaidh and Cormac Cas!
How they left Munster to be shared
Justly among their fair offspring.
And as a result of the womans discourse Cinneide left the sovereignty of Munster to Ceallachan.
[The treachery of Sitric and the Vikings]
After this the Lochlonnaigh [Norwegians, Danes, Vikings] seized on Ceallachan by treachery, and the siol Eoghain and the Dal gCas rescued him in spite of them. But when Ceallachan and the Munster nobles had defeated the Lochlonnaigh in many battles and had driven them out of Munster, Sitric, son of Turgesius, who was their leader, hit upon the plan of arranging a match with Ceallachan, to wit, to give him his own sister Beibhionn, daughter of Turgesius, to wife, and to allow him to possess free the two provinces of Munster, without retribution or claim respecting them on the part of the Lochlonnaigh; in order that when Ceallachan should go under his own protection to marry his sister, himself and all the Munster nobles who were with him might be slain; and he communicated the secret of this plot to Donnchadh, son of Flann, king of Tara, who was at enmity with Ceallachan through his not having paid him the rent for Munster, and hence he consented to Sitrics carrying out his treacherous design on Ceallachan and the Munster nobles. Thereupon Sitric sent envoys to Ceallachan to give tidings of the match, and when they came into his presence, what he proposed to do was to take a large host with him when going to marry the lady. "That is not right," said Cinneide, son of Lorcan, for it is not right to leave Munster without defence and what thou shouldst do is to leave a force to hold Munster and to take four score lords sons with thee on going to marry the lady."
And this was the :counsel they adopted. And as Ceallachan was going on this journey; the night before he arrived in Ath Cliath [Viking Dublin], Mor, daughter of Aodh, son of Eochaidli, daughter of the king of Inis Fionnghall, wife of Sitric, asked why he was making a match with Ceallachan, seeing he had slain so many Lochlonnach nobles. "It is not for his good this match is arranged by me," he answered, "but with a view to practising treachery against him."
[Mor's warning to Ceallachan]
At these words the lady started, as she had been long secretly in love with Ceallachan from the time she saw him at Port Lairge [Waterford]; and she rose early the next morning and went secretly along the path on which she thought Ceallachan was coming; and when he came up to her she took him aside and informed him of the plot which Sitric was hatching against him in order to kill him; and when Ceallachan thought of returning he was unable to do so, as the fields on either side of the road were full of companies of Lochlonnaigh ambushed for the purpose of capturing him. As he made an effort to return they sprang upon him from all sides, and a body of nobles who were with him were slain, and these in their turn slew a number of the Lochlonnaigh. But the bulk of the host bore down on Ceallachan and there captured himself and Donn Cuan, son of Cinneide, and they were taken to Ath Cliath [Viking Dublin] as prisoners, and thence to Ard Macha, where nine Lochlonnach earls with their detachments detained them.
[The land and sea forces sent to rescue Ceallachan]
As to the company of Munster nobles who escaped from this conflict, they proceeded to Munster and told the news to Cinneide, who thereupon got ready two hosts to go in quest of Ceallachan, that is, a land force and a sea force, and he made Donnchadh, son of Caomh, king of the two Fearmaighes, leader of the land force, and Cinneide proceeded to encourage him, telling him that eleven of his ancestors were kings of Munster, to wit, Airtre, Cathal son of Fionghaine, Fionghaine son of Cathal, Cu gan Mhathair, Cathal who was called Ceann Geagain, Aodh., Flann Cathrach, Cairbre, Criomhthann, Eochaidh, and Aonghus son of Natfraoch. Besides, Cinneide sent ten hundred of the Dal gCais along with him with three Leaders over them, to wit, Coscrach, Longargan and Conghalach, as says the poem: Let twenty hundred go northwards.
Here is the stanza of this poem which quotes the words of Cinneide:
Let Coscrach, of the battles, go there.
And Longargan, the lovable,
Let Conghalach. from the lake, go;
I mean my three brothers.
Moreover, Cinneide sent thither five hundred more of the Dal gCais with Sioda, son of Sioda of the clann Cuilein, and five hundred more of the Dal gCais with Deaghaidh, son of Domhnall, besides the fighting men that went thither from the other free-born tribes of Munster. The second great force he sent by sea with Failbhe Fionn, king of Desmond, as their leader.
As to the land-force they proceeded from Munster to Connaught; and they sent skirmishers to Muaidh and to Iorrus and to Umhall to bring cattle preys to the Munster camp, and the camp were not long waiting for the return of the skirmishers when they saw a host in good array approach them, and their numbers was ten hundred. and a single youthful warrior at their head; and when they came up, Donnchadh, son of Caomh, asked what force was that. "A body of Munstermen," he replied, "to wit, the Gaileanga and the Luighne of the race of Tadhg son of Cian, son of Oiliil Olom, and the men of Dealbhna, of the race of Dealbhaoth, son of Cas, son of Conall Eachhiaith, who are giving you a helping hand through brotherly sympathy in opposing the foreigners and in rescuing Ceallachan from them. And there are three valiant leaders at the head of this force, to wit, Aodh, son of Dualghus, having all the Gaileanga under him, Diarmaid, son of Fionnachta, having the Luighnigh under him, and Donnchadh, son of Maoldomhnaigh, at the head of the men of Dealbhna; and as a testimony of this is the historical poem which begins with this stanza:
The clanna Cein are there,
And the Dealbhaoith all together
Coming to the hosting [expedition],
And they will fight on your side.
Now this host was thus constituted. Five hundred of them had swords and shields, and five hundred were archers. The Munster host and this force who had come to help them proceeded thence to Tir Chonaill and they spoiled the country. Muircheartach, son of Arnaladh, came to Donnchadh son of Caomh, and asked him to restore the cattle preys with good will; and Donnchadh replied that he would only give him what remained of the preys after the hosts had been satisfied. Upon this Muircheartach left the host and sent envoys secretly to the sons of Turgesius to Ard Macha informing them that the Munster host were in quest of Ceallachan and intended to rescue him.
[The expedition and battle to rescue Ceallachan]
As to the sons of Turgesius, they set out from Ard Macha, nine earls with their host of Lochlonnaigh, and Ceallachan and Donn Cuan with them as prisoners. And the Munster host proceeded to Ard Macha and slew all that came in their way of the Lochlonnaigh, and when on the next day they heard that Sitric and his host had gone to Dun Dealgan with Ceallachan they set out in pursuit of them, and when Sitric observed them coming near the town he himself and his host betook themselves to their ships, having Ceallachan and Donn Cuan with them, and the Munster host came on the verge of the strand in front of them and held a parley with the Lochlonnaigh. And thereupon they saw a large fleet approach them in the harbour, and the Munstermen knew that it was Failbhe Fionn and his fleet that were there.
Failbhe and his fleet proceeded by direct route to meet the Lochlonnaigh, and he made an attack on the ships in which were Sitric and Tor and Maghnus, and he boarded Sitrics ship, having a sword in either hand, and set to cutting the ropes that bound Ceallachan to the mast, with the sword that was in his left hand, and set Ceallachan free, and let him down on the ships deck, and then gave Ceallachan the sword he held in his left hand. Ceallachan went from Sitrics ship to that of Failbhe; and Failbhe continued to hew down the Lochlonnaigh until they overpowering him, slew him and cut off his head. Fianghal, a leader of his followers, took his place in the conflict, and seizing Sitric by the breast by force, cast both of them overboard, and they went to the bottom and thus were drowned.
Seaghdha and Conall, two other leaders, came on and seized Sitrics two brothers, to wit, Tor and Maghnus, and threw them overboard, so that the four were drowned in that manner. And in like manner acted every other company of the Gaels [Irish]; they sprang on the Lochlonnaigh and broke them up, made gaps through them, slew them, and threw them into disorder, so that there escaped from them only a few who were saved by the swiftness of their ships, and they went on land with Ceallachan who had thus been rescued from Lochlonnach captivity by the valour and prowess of the Munstermen; and thence they proceeded to Munster with Ceallachan, and he resumed the government of his own country.
And as they were setting out from Ath Cliath for Munster, Murchadh son of Flann, king of Leinster [the southeastern province of Ireland], sought to give them battle for having slain so many Lochlonnaigh in rescuing Ceallachan from them. But when they saw how brave and valiant the Munstermen were, they allowed them to pass without giving them battle,
XXIII.
But when Ceallachan returned to Munster he considered how severely the Lochlonnaigh oppressed Munster, and he himself and the nobles of Munster resolved to attack them with a view to banishing them; and they first made a sudden attack on Luimneach, and Ceallachan and his host slew five hundred of them and took away hostages from them. After this he plundered Corcach and brought hostages and treasures therefrom. He also plundered Cashel, and three hundred Lochlonnaigh were slain there. Thence he went to Port Lairge [Waterford] and took possession of the town and plundered it, and he inflicted a severe defeat on Sitric, son of Iomhar, and slew five hundred of his people; and Sitric himself took flight in his fleet; and Ceallachan returned to Domhnall OFaolain, king of the Deise, and gave him his own sister Gormfhlaith, daughter of Baudhachan, to wife. Soon after that Ceallachan died, . . . " (Keating 1908:223-233).