
O’Brien dynasties of Limerick as Domnall Mór came to power
As Domnall Mór came to power, the city of Limerick was surrounded by different O’Brien and Dál Cais groups. Domnall himself was a member of the Uí Thairdelbaig, the ruling dynasty which not only produced Brian Boru but also his most powerful successor, Muirchertach, the Irish high-king who gave Cashel to the Church in 1101. As discussed in a previous post, the territory of this dynasty included their dynastic base at Killaloe and the lands immediately to the east of that town but they stretched down into the area around Castleconnell, where Domnall Mór had his own hall [a thech féin] in 1175. [Castleconnell is marked with a yellow cross on the map above.]
The annals make it clear that these various groups, as well as rival candidates amongst the Uí Thairdelbaig were all jockeying for position as Domnall‘s father began to lose his grip on power in the later 1150s. When choosing a king, the medieval Irish did not follow the system of primogeniture but instead opted for those showing leadership qualities or febas. The list of necessary attributes, as with politicians today, could range from bellicosity to shrewd negotiating ability, depending on the circumstances in which the kingdom found itself. A perennial favourite (again, similar to today) were good looks while another was a close relationship to the preceding king.
In a world where men tended to marry for strategic reasons and where temporary partnerships (in addition to one’s lawfully wedded spouse) were socially acceptable, this did little to minimise the potential group of those who were rígdomna or capable of being made king. Provided the king recognised the child, all his offspring were deemed royal although there were clearly question marks about female claims on occasion; there are stories of saints helping the unborn to point out an infant’s less prestigious father at public assemblies. Brothers of the preceding king, who could often be much younger than their sibling, were also very much in the mix as Bart Jaski has made clear. Violent infighting amongst rival candidates, particularly as a king grew old or sick, was commonplace.

One of the carved twelfth-century heads from the recently restored Cormac’s Chapel, Cashel
Domnall Mór was a grandson of Diarmait Ua Briain, ruler of Waterford and brother of the late eleventh/ early twelfth-century high-king, Muirchertach. It was not Domnall’s father but another of Diarmait’s sons, Conchobar Slapar Salach “Dirty Bandage”, who seems initially to have been the strongest O’Brien leader within his generation. Conchobar is identified as king of Munster in an entry for 1130 when he said to have captured a thief who stole jewels from Clonmacnoise. The thief was hung at Cluain Briain, in the parish of Athlacca which the later O’Brien genealogies identify as part of the holdings of Conchobar in south county Limerick and north Cork. Immediately after the death of Domnall’s father, Toirdelbach, in 1167, a grandson belonging to this south Limerick branch of the family was involved in the jockeying for inheritance of the O’Brien leadership:
“Muirchertach[of Dún na Sgiath – Fort of the Shields] son of Tairdelbach Ua Briain, was slain by Conchobar grandson of Conchobar [Slapar Salach] and that same Conchobar was slain on the third day after that by Ua Faeláin. And much slaughter was inflicted by the men of Thomond on one another.”

Other annalsadd the details that this Muirchertach of Donaskeagh, Co. Tipperary was also identified, at least by some, as king of Dál Cais and as lord of Thomond. He was a step-brother, through his mother, of the contemporary king of Connacht and one annalist states that the Waterford Ua Faeláin (or Whelan) lord, who killed Conchobar, did it on the Connacht ruler’s behalf. (One of the features of the internecine wars between dynastic rivals was the search for powerful patrons who could support them in their ambitions and it seems that in the case of Muirchertach, this was the O’Connor ruler of Connacht.) Another annalist, located far away at Armagh, claimed, in contrast, it was not Connacht but the MacCarthys of south Munster who were involved. The discrepancy may be simply due to difficulties in acquiring accurate information or it may represent different people each apportioning blame where it suited them best. It is rare, after all, for political analysts to always agree in any era!
In the year before his murder, in 1167, Muirchertach had accompanied the Connacht king on a successful military expedition involving twenty battalions of foot soldiers and cavalry going north to Tyrone, together with a fleet from Donegal. On returning to the royal Connacht base in Tuam, the high-king gave Muirchertach his father’s drinking horn as tuarastal – the word used for gifts given by superiors to their juniors to reward loyalty. The Connacht king is then said to have ridden with the MacCarthy ruler leader south to Knockainey (but no mention is made of O’ Briens in this pro- MacCarthy source). Perhaps Mac Carthaigh dropped poison in the high-king’s ear about his north Munster rival or perhaps it was the death of Muirchertach’s father in the interim which changed the political imperatives but for whatever reason, the alliance between Thomond and Connacht apparently broke apart within the year to the point that locals believed that Ruaidrí of Connacht was fostering civil war amongst the Thomond leaders.

Portrait of a king from the Cistercian abbey of Knockmoy, Co. Galway founded by Ruaidrí’s grandson and king of Connacht, Cathal Crobderg. Photo taken from Monastic Ireland Facebook page.
Whoever or whatever brought it about, the elimination of two strong rivals left the way open for Domnall to emerge from the pack of potential candidates. There was one remaining enemy, Brian of Slieve Bloom, the man who controlled the relatively new Dál Cais colony kingdom of Ormond (see preceding post). Domnall had him taken prisoner and blinded. Again, the Connacht king Ruaidrí may have played a role in this; the Annals of the Four Masters state that in the same year, Ruaidrí and his ally, Tigernán Ó Ruairc of Breifne (modern Cavan/Leitrim), brought their troops south to Knockainey, took hostages and divided Munster between the MacCarthys in Cork and Domnall Mór in Limerick. [This division of Munster had been a consistent policy of the O’Connor kings for at least two generations]. 720 cows were given to Ruaidrí by the southern lords on this occasion as a fine for having murdered Muirchertach. (Just how murky this all was depends on one’s tolerance for conspiracy; it is not particularly hard to imagine Ruaidrí having both connived at the death of the Thomond ruler and then subsequently acting the outraged overlord and punishing the murderers.) This is the second Knockainey reference in the space of two years – as the home of important O’Brien churchmen (the Uí Enna) while also being a traditional base for MacCarthy ancestors, it may well have been seen as a key location for judicial and other assemblies in this era. Again, however, the sources are not entirely consistent – the Armagh annalist states that the assembly took place at Pallasgreen held by the O’Brien lords of Coonagh.
This last was an O’Brien dynasty which was not recorded in the later twelfth century annals but it is impossible to believe that they did not form part of the contemporary political scene. These were the descendants of Donnchad, son of Brian Boru, who had retained his position as leader and king of Thomond for almost fifty years until his death in 1064 and who is recorded, in his more successful phases, as both king of Munster and high-king of Ireland. Donnchad’s son Murchad was active in the 1050s and 60s until his death in Longford in 1068 and his grandson, Brian of Glenmire is documented in the early twelfth century. It is said in fourteenth-century genealogies that Brian took his name from a battle at Glenmire in 1127/28. These same genealogies finish with two sons of Brian, Cennétig and Donnchad and later, early modern, additions state that these men were associated with Uí Briain lordships in Coonagh and Aherlow respectively. Brian Hodkinson has identified 13th C O’Briens active in Aherlow which tends to confirm the existence of these families at an earlier period than the late date of the genealogies might suggest.
Of course, Domnall Mór’s enemies were not limited to his local dynastic rivals. At the time that he was coming to power, the scene was being set for the Norman invasion and the year of his accession, 1168, was just before the fleet of Robert Fitzstephen arrived in Bannow Bay in May 1169 with a small army of knights and foot soldiers. Fitzstephen had met Diarmait mac Murrough while the latter was in exile at the court of the king of south Wales, Rhys ap Gruffydd and fighting for the possibility of control of Wexford and surrounding territory was a more pleasing prospect than joining Rhys in fighting the Angevin king, Henry II. The successes of Fitzstephen’s men, both in conquering Wexford town and defeating the men of Ossory prompted the Connacht king into action. In the words of the Norman writer, Giraldus:
“Sending emissaries in all directions, he quickly called together the principal men of the whole island. When they had consulted with each other, they immediately and with one accord took up arms against Diarmait and gathered many armies and an infinite number of men to attack the part of Leinster called Ui Chennselaig.”
Where did this leave Domnall who seems to have been no friend to the ruling dynasty of Connacht? The Annals of the Four Masters suggest he was not involved and that this great host was, in fact, essentially a midlands affair, involving men from the broad belt of lands stretching from north Galway across to Cavan and down to Westmeath. Domnall’s unwillingness to participate could well be related to the alliances he had made with potential patrons prior to becoming the Thomond king, when he seems to have married one of Diarmait’s daughters. Alternatively, as Marie Therese Flanagan has suggested, he may have quickly chosen his bride and his father-in-law in the short months following Fitzstephen’s arrival in Ireland. Domnall may even have attacked Ruaidrí in the rear once the latter had left for Leinster for, as soon as he had received Diarmait’s hostages, Ruaidrí immediately returned west and mounted a two-prong attack on Thomond. His allies, the Uí Maine (from the large kingdom around Athlone and the Suck), attacked the Ormond part of Domnall’s kingdom while Ruaidrí brought a fleet south along Lough Derg and burnt the bridge at Killaloe. In what may well have been part of the same campaign, the MacCarthy leader attacked Limerick, burning the market and half the fortress.

The modern bridge of Killaloe
Fending off Connacht attacks along the Shannon had been a feature of Thomond life for over a hundred years. On this occasion, however, Domnall was able to draw on Diarmait’s well-armed mercenaries for aid. Giraldus, our only source for this, states that with the help of Fitzstephen and his men, Domnall was “everywhere victorious after a number of battles” and that “Ruaidrí withdrew humiliated to his own territory and completely gave up his claim to the kingship.” Since Ruaidrí attacked Dublin the following year, one might well query this conclusion but on the whole and notwithstanding the attacks on Killaloe and Limerick, Domnall appears to have successfully consolidated his grasp on the Thomond kingship by the end of 1170. His potential rivals locally had been largely eliminated and he had apparently neutralised the perennial Connacht threat to Thomond for the time being. He had also, and this was to prove an important precursor for the future history of his kingship, entered into mutually profitable relationships with Diarmait’s Norman mercenaries.
Unfortunately for Domnall, Diarmait’s mercenaries had now been supplemented by Strongbow’s new troops, led by an advance guard under Raymond le Gros, Fitzstephen’s nephew. Landing close by, at Baginbun, these began a campaign to take Waterford which culminated in Earl Strongbow’s marriage to Diarmait’s daughter. Aoife, in that city. Turning their attention to Dublin, the newcomers then moved north. The MacCarthys attacked the garrison which had been left behind to defend the southern port but although, apparently successful in their initial attempts, they were ultimately defeated. Diarmait died in May 1171 and the loss of his father-in- law’s patronage seems to have forced Domnall into joining O’Connor’s subsequent attack on Dublin.
Whereas Diarmait had sought help from the Norman dynasts based in Wales, Ruaidrí called on men from the Hebrides and from Man to help him in his attempts to besiege Dublin and to defeat the Leinster king. There are also hints that the northern Irish kings were calling on the help of a sea fleet from the Orkneys at the same time. Foreign mercenaries, working for pay, had been a feature of the Irish political landscape since at least the beginning of the twelfth century, if not as far back as the battle of Clontarf and Andy Halpin has analysed the archaeological evidence which suggests that these men enjoyed some of the most up to date military equipment of their day and that they tended to congregate, in particular, in the Scandinavian seaports of Ireland. The hinterland of Scandinavian settlement around each of these ports suggest that, in at least some cases, these men could be paid in land, resulting in permanent colonies of military men who could be called upon to fight for their overlord. Domnall’s use of Fitzstephen’s men, in short, fitted in with a pattern of Thomond warfare which stretched back to the days of his ancestor Brian Boru.

Hiberno-Norse arrowheads from the excavations at King John’s Castle, edited by Ken Wiggins, ‘A place of great consequence’ (2016), p.412
As is well known, however, the Angevin King Henry II decided that, with the death of Leinster king who had sworn him personal loyalty, and the subsequent retention of the rich trading city of Dublin by his mercenaries, he needed to reinforce his overlordship over the Irish lands which were falling into Norman hands by gift, inheritance and conquest. Before his fleet set sail from Milford Haven, Henry had already extracted from Strongbow a pledge to surrender to royal authority Dublin, its adjacent cantreds ‘and also the coastal cities and all castles”. This is twenty-twenty hindsight on Giraldus’ part to some extent for Strongbow was not in a position to offer more than a fraction of the east coast settlements. Even Wexford was under the control of the local citizenry who had imprisoned Fitzstephen.
Henry’s fleet of 240 ships was considerably larger than that of Fitzstephen’s three ships or Strongbow’s force who had brought with him a total force of between 1200 and 1500. Henry, in contrast, brought five hundred knights as well as both mounted archers and food soldiers, perhaps 4000 in all. We have records of some of the supplies that came over with the royal army:, over 4000 hogs as well as wheat, beans and oats to feed them (as well as 569 lbs of almonds for the leadership); military equipment such as 3000 odd pickaxes, 60,000 nails, 2 wooden towers, canvas for spare sails, spades, and warhorses as well as gerfalcons for hunting, silks, ceremonial robes and gold to ornament the king’s swords. This was an expedition intended to impress and overawe the locals rather than the small, workmanlike parties of hired mercenaries, led by impoverished young men down on their luck that Diarmait Mac Murchada had initially attracted.

Gerfalcons are an Arctic falcon of a type exported by Norwegian kings in the later twelfth century
While Henry was still in Waterford, the Wexford men offered him their prisoner, Fitzstephen, in an attempt to curry favour: “the king consigned him to Raghnall’s tower for safe keeping, firmly fettered and chained to another man. Just after this, king Diarmait [MacCarthy] of Cork arrived. He was drawn forthwith into a firm alliance with Henry by the bond of homage, the oath of fealty and the giving of hostages; an annual tribute was assessed on his kingdom and he voluntarily submitted to the authority of the king of England. The king moved his army from there and went first of all to Lismore where he stayed for two days and from there continued to Cashel. There, on the next day, Domnall king of Limerick met him by the river Suir. He obtained the privilege of the king’s peace, tribute was assessed on his kingdom in the same way as on Diarmait’s and he too displayed his loyalty to the king by entering into the very strongest bonds of submission.”

Portrait of Henry II from MS 700, National Library of Ireland, an illuminated copy of Giraldus’ writings.
As a result of this arrangement, Henry sent custodes and ministrii to both Cork and Limerick – phrasing which may imply both a military and an administrative presence in the two Munster cities. Henry was not only the most important monarch in western Europe; he was also a battle-hardened veteran who had spent the previous twenty years fighting to keep control of his vast territories and to control the various local English interest groups which had flourished during his mother’s twenty-year civil war. According to Giraldus, the MacCarthy and O’Brien submissions were matched by those of the king of Ossory and the Whelan lordship of the Deise, all men whose lands were within easy striking distance of the troops massed at Waterford city. Once he had arrived at Cashel, Henry was already on territory where O’Brien archbishops had been the key authority for the previous forty years. Furthermore, the Connacht fleets had just spent the winter on Lough Derg as well as burning Killaloe the previous year so Domnall’s room to manoeuvre and ability to make defensive alliances was severely limited. Irish kings were used to giving hostages and indeed to swearing oaths in order to gain peace; as far as we know, they had never let these constrain their subsequent actions once the immediate crisis had passed. Swearing allegiance to Henry freed Domnall from being forced into alliance with Ruaidrí and that seems to have been the main consideration.
Certainly Domnall does not appear to have felt intimidated for long. By 1173, with Henry’s great army gone and in the face of pinprick attacks on his western borders by the lords of the Shannon estuary, Domnall mounted a successful attack on Kilkenny and subsequently on Waterford. The following year, he fought a major battle at Thurles in the territory of his mother’s people where almost 700 troops and four knights of an invading force from Dublin were slain. The remnants retreated back to Waterford where an uprising of the local citizenry killed the constable and two hundred others. As a result, Domnall felt sufficiently secure to attack Kerry the following year. He also took the opportunity to kill one of the north Kerry hostages in his house at Castleconnell as well as blinding his cousin Tadhg and a Mathgamain O’Brien who may have been from the south Limerick branch in Athlacca. These were all locations where O’Brien leaders have been fighting since the beginning of the twelfth century; for Domnall, life seemed to have returned to normal.
However, the original mercenary leaders in Strongbow’s contingent as well as their Leinster allies wanted their revenge for Thurles while the Connacht high-king remained determined to enforce his authority over Limerick. (It is worth remembering that Connacht lacked an important seaport at this point as Galway had not yet begun to be developed.) Again, he brought his fleet down the Shannon, this time apparently banishing Domnall into Ormond and installing a new puppet-king who was apparently a son of his murdered step-brother, Muirchertach.
According to the Annals of Tigernach, a pro-Connacht source, Ruaidrí convinced Strongbow’s contingent to attack from the east at around the same time. There is nothing particularly unlikely about this; by October 1175, Ruaidrí had signed the Treaty of Windsor with Henry which stated that he could call on the ‘constable of the king of England’ to assist him if any should rebel against his overlordship or refuse to pay the tribute in hides which was now owed to both Ruaidrí and to the English king. In fact, Giraldus states explicitly that it was at this point that Domnall became arrogant and, displaying a lack of respect as well as treachery, went back on the oath of loyalty which he had made to the king. The Annals of Inisfallen make no explicit mention of this Connacht involvement however but simply state that the two most powerful kings in Munster were subjected in this campaign, an arrangement that Connacht kings had been attempting to enforce since the beginning of the century :
“The grey foreigners, the son of Mac Murchada and Ua Gilla Pátraic came from Dublin to Limerick and thence to Múscraige Áeda [north Cork] and they plundered Ballyhay and Cooliney. Cormac’s son [MacCarthy king] made peace with them and they left the hostages of Desmond with him.”
The siege of Limerick at the onset of this expedition is described at length by both Giraldus and the author of La geste des Engleis en Yrlande, otherwise known as the Song of Diarmait and the Earl. The army was led by Raymond le Gros and his nephew Meiler Fitz Henry and consisted of 120 knights, 300 mounted archers and 400 soldiers on foot (who were also armed with bows). It is known that Limerick had been walled with gates and fortifications (doirsi do dunad ..ocus tuir) since at least the 1120s when a description of a battle within its streets occurs in the saga Caithréim Ceallacháin Caisil. Today, it is only the Shannon which can be forded at low tide but presumably, in the days before it was channelled, the Abbey river would have also been accessible in the same way although it is stated that the river was deep and that the only ford was ‘difficult’. It did not however, prove impassable to horses and only four men were apparently drowned getting across to King’s Island.

Low tide on the Shannon on either side of the city
Giraldus states that the defenders had stones and javelins (lapidii iaculiique) which were thrown both from the walls and from the river banks. It seems likely, however, from both the arrowheads found in excavations under the castle and from the fact that the Irish word for bow, boga, is borrowed from Old Norse, that they also had bows. The various missiles were, however, unavailing against the helmets, shields and horses of the besiegers and the men on the river bank were driven into the city where the houses of the merchants were looted for their gold and silver. Provisions were then brought inside the walls and a garrison, amounting to nearly half the Norman troops, was left to control it while Raymond, as commander of the attacking force, went back to Leinster where he received a recall to Britain. In those circumstances, Domnall was able to mount a counter-attack in the spring, and when news of this was brought to Strongbow, he insisted that Raymond should return to Limerick to bolster its defences. Despite meeting opposition around Cashel, this too was successful and the Normans once again entered Limerick on the third day of Easter. Conscious perhaps, that he was unlikely to be left in situ, Raymond then undertook negotiations between Domnall and Ruaidrí, moving between Domnall, to the west of Limerick city and Ruaidrí north of Killaloe. As a result, booty and provisions, apparently drawn from MacCarthy lands, once again flowed to the Limerick garrison and Domnall gave up seven hostages to Ruaidrí to be kept by the occupying force of Limerick. It is during this period that the Limerick garrison is said to have attacked the estuary base of Scattery Island, the first sheltered harbour available to ships coming up the Shannon from the Atlantic coast. It seems clear that although Limerick was not amongst the lands explicitly listed as belonging to the Angevins in the Treaty of Windsor, a primary aim of this campaign was to ensure that it, too, effectively came under their own control.
While Raymond’s campaign in south Munster was still continuing, he was told of Strongbow’s death. This meant that occupying Limerick, “so remote and hemmed in on all sides by innumerable enemies” as Giraldus puts it, became a luxury that could not be afforded by those who wanted to ensure the survival of Strongbow’s inheritance. Instead, the entire garrison would return to Leinster and the city of Limerick was returned to Domnall’s keeping as a vassal of the king of England. Hostages and oaths notwithstanding, however, Raymond’s troops still had sight of the city when they realised that Domnall was burning the new bridge they had built, linking King’s Island to the mainland. What Giraldus describes as the strongly fortified walled city of Limerick, adorned with buildings (edificiis decenter ornata,) and full to overflowing with provisions gathered in from every quarter, would henceforth remain in Domnall’s hands for the rest of his career.

Royal MS 13 B VIII in the British Library is another illuminated copy of Giraldus (f.27v)
It is important to remember, however, that this decision to burn the bridge and possibly the garrison’s quarters, was not an expression of ethnic hatred. The garrison had, after all, decided to withdraw precisely because they knew that their control of Limerick could not be sustained if they remained; they hardly thought, therefore, that they would continue to hold it in their absence. Giraldus may dress up his account with rhetorical flourishes about shameless acts of perjury, impudent faithlessness and the treachery of all Irishmen but in reality, Domnall was simply ensuring that his important city of Limerick, the only major seaport on the west coast, would remain in his hands and would be defensible in any future engagements with Norman fighting forces. Within the year, indeed, Domnall was helping Miles de Cogan and the Fitz Stephens turn the speculative gift of the kingdom of Cork, awarded to them by Henry in May 1177, into real landholdings at the expense of the MacCarthys of Cork.

Giraldus’ dislike of Domnall Mór Ua Briain is also illustrated by his story of the bearded lady living at Domnall’s court in his account of the marvels and wonders of Ireland
In 1978, F.X. Martin wrote that in these initial years of the conquest, Domnall “had performed several political somersaults” but this judgement is based on prioritizing Domnall’s relationships with Norman adventurers over all others. On the contrary, if we understand Domnall to have been primarily concerned with fighting off the hereditary enemies of the Thomond kingdom to the south (MacCarthys) and to the north (O’Connors) and that he simply saw the rival Norman factions, and even King Henry himself, as tools to be exploited in those aims, than his actions appear perfectly consistent.



































































