Ruaidhri O Conchubhair assumed the sovereignty of Connaught and the greater part of Leath Cuinn, because the king of Oirghiall, the king of Meath and the king of Breithfne submitted to him, and, moreover, he is called king of Ireland in the seanchus. Still he was only a king with opposition, that is, a king to whose possession of the sovereignty of Ireland a great many of the Irish nobles were opposed. And it was while Ruaidhri reigned in this manner that the wife of Tighearnan Caoch O Ruairc (Dearbhforgaill was her name, and she was daughter to Murchadh Mac Floinn, king of Meath, and not wife of the king of Meath as Cambrensis says) sent messengers in secret to Diarmaid Mac Murchadha asking him to come to meet her and take her with him as his wife from Tighearnan and she told the messengers to make known to Diarmaid. that Tighearnan had gone on a pilgrimage to the cave of Patrick's Purgatory, and that, therefore, he would have an opportunity of quietly carrying her with him to Leinster. There had been indeed an illicit attachment between them for many years previously.
As to Diarmaid, when this message reached him he went quickly to meet the lady, accompanied by a detachment of mounted men, and when they reached where she was, he ordered that she be placed on horseback behind a rider, and upon this the woman wept and screamed in pretence, as if Diarmaid were carrying her off by force; and bringing her with him in this manner, he returned to Leinster. As to Tighearnan, when he returned to Breithfne and heard that it was against her consent his wife was taken from him, he made a complaint of this outrage to Ruaidhri O Conchubhair and to his. friends in general.
Upon this Ruaidhri made a muster of the men of Connaught, Breithfne, Oirghialla and Meath, and set out with a large host to waste Leinster to avenge this evil deed Diarmaid had done.
When Diarmaid heard that Ruaidhri was marching to waste Leinster, he assembled and brought together the nobles of Leinster from all sides, and when they came to one place their answer to Diarmaid was that they would not go to defend the evil deed he had done, and thereupon many of them deserted him and put themselves under the protection of Ruaidhri, and made known to him that Diarmaid before that time had committed many acts of injustice and tyranny against them.
As Diarmaid was not strong enough to fight Ruaidhri, the latter set about spoiling the territories of all the Leinstermen who sided with Diarmaid; and he went on to Fearna and levelled Diarmaid's house, and broke his fortress, and banished him out of Ireland altogether. And Diarmaid went to Henry II., king of England, who was then in France; and when he had come into the king's presence, the latter welcomed him and showed him much friendship; and when he made known to the king the cause of his visit, the king wrote friendly letters to be taken by him to England, in which he gave permission to all who so wished to go with him to Ireland to help him to recover his own territory. Diarmaid, on this, bade farewell to the king, and proceeding to England arrived at Bristol, and caused his letters to be read there publicly; and he made large promises to those who would go with him to Ireland to recover his own territory.
It was there he met Richard Fitz Gilbert, son of earl Stranguell; and he made a compact with him, to wit, to give his own daughter, that is, Aoife, daughter of Diarmaid, to wife to him, and with her the inheritance of Leinster after his own death, Richard to be obliged to follow him to Ireland to recover his territory for him. After they had made a compact on these conditions, Diarmaid went to Wales to a prince who was there called Ralph Griffin, who ruled the country under king Henry, and made his case known to him. At that time the prince kept in prison a powerful nobleman of great achievements called Robert Fitz Stephen, for having disobeyed the king, and there was no relief forthcoming to him unless he chose to go to Ireland to aid Mac Murchadha by the strength of his arm in the recovery of his territory. And when the bishop of St. David's and Maurice Fitz Gerald heard that Mac Murchadha had visited this prince requesting him to free Robert Fitz Stephen from his captivity, they themselves came to request him in like manner to set Robert at liberty, and let him go to Ireland with Mac Murchadha. Now that bishop and Robert Fitz Stephen and Maurice Fitz Gerald were uterine brothers.
The prince then released Robert on condition that he would follow Mac Murchadha to Ireland the next summer. Diarmaid, on the other side, promised Robert Fitz Stephen Loch Garman and the two cantreds next it, as his property for ever, in return for his coming to help him to fight his enemy; and after this compact was made, Diarmaid bade farewell to these people and proceeded with only a small force to Ireland. Having landed in a place where he had many enemies and few friends, he went secretly to Fearna Mor Maodhog, putting himself under the protection of the clergy and community of Fearna; and he stayed with them sad and wretched during the time that elapsed until the coming of summer.
As to Robert Fitz Stephen he came to fulfil his promise to Mac Murchadha, and the number of the host that came with him to Ireland was thirty knights, three score esquires and three hundred foot; and the place where they landed was at Cuan an Bhainbh on the south coast of the County of Loch Garman in the place which is called Baginbun, and it was then the year of the Lord 1170, and the seventh year of the reign of Ruaidhri O Conchubhair. There was also a distinguished knight with Robert Fitz Stephen at that time, to wit, Herimont Morti, a knight of the party of the earl of Stranguell, whom he sent before him to Ireland to study the country, and when they landed Robert sent word to Diarmaid to make it known to him that he had arrived in Ireland.
When Diarmaid heard this he rejoiced, and went to meet them with five hundred warriors; and when they had come together they proceeded by agreement to attack Loch Garman with a view to getting possession of it; and when they were approaching the town, the burgesses came to the decision of submitting to Diarmaid, and of giving him four of the nobles of the town as hostages for their maintaining peace and paying him rent and tribute and for their being obedient to him as their lord. It was then that Diarmaid bestowed Loch Garman and the two cantreds next it on Robert Fitz Stephen, and, moreover, he bestowed the two cantreds next again to these on Herimont Morti, according to the promise he had made them in Wales; and after he had fulfilled this promise Diarmaid assembled his own people and the foreigners to one place; and the number of the host that assembled there was three thousand men, counting Gaels and foreigners; and they proceeded thence of one accord to plunder and spoil Osruighe; and the king of Osruighe at that time was Donnchadh, son of Domhnall Reamhar, an inveterate enemy of Diarmaid, and as they had come to waste Osruighe, while Donnchadh could not defend himself, he, with the nobles of his country, decided to give Diarmaid hostages for the payment to him of head rent; and thus Diarmaid was prevented from wasting the country.
Now when the nobles of Ireland heard of the arrival of Diarmaid and of these foreigners and of all the successes with Ruaidhri O Conchubhair, king of Connaught, who then held the sovereignty of Ireland; and what they agreed upon was to give him an auxiliary force from every province of Ireland; and when these forces had assembled in one place Ruaidhri marched with them to Ui Cinnsealaigh in the hope of driving Diarmaid and the foreigners from Ireland; and when Ruaidhri went into Leinster, Diarmaid and the foreigners, and as many of the Leinstermen as followed him, went into the dark fastnesses of the woods near Fearna Mor Maodhog to shield themselves from the great force of Ruaidhri's hosts. But as Ruaidhri saw that they were not going to give him battle he sent envoys to Robert Fitz Stephen asking him to quit the country, saying that he had neither right nor hereditary claim to be in it. Robert said, in reply to the envoys, that he would not desert the lord with whom he had come to Ireland. The envoys returned with this answer to Ruaidhri, and when he heard it, and heard also that Mac Murchadha would not on any account forsake the foreigners, he resolved to make a sudden attack with all his forces regular and contingent on Diarmaid and the foreigners and upset and destroy them.
When the Leinster clergy saw that the country was in danger of being thrown into disorder and destroyed by this conflict, they did their best to bring about peace between Ruaidhri and Diarmaid; and these were the terms in which this peace was concluded, to wit, Diarmaid to have the province of Leinster which he had inherited, and to be obliged to be obedient and faithful to Ruaidhri, as every king of Leinster was bound to be to the kings of Ireland, and in pledge for the fulfilling of the terms of this peace Diarmaid gave one of his sons named Art to Ruaidhri as a hostage. Moreover Ruaidhri promised to give his own sister to Diarmaid to wife; and on these terms they separated from one another in peace; but Diarmaid promised Ruaidhri not to bring any more of the foreigners to Ireland; and soon after this Maurice Fitz Gerald came to Ireland in the beginning of the summer according to the promise he had given to Mac Murchadha, and also because of the reward which Mac Murchadha had promised to himself and to Robert Fitz Stephen the previous autumn on condition of their coming to Ireland to help him to recover his own territory; and the number of the hosts who came with Maurice on that occasion was ten knights, thirty esquires and one hundred foot, and the place where they landed was at Loch Garman.