Munster in the Early Annals of Ireland

O Brian's siege of 1132

Naval-based warfare became something of a regular occurrence in early 12th century Ireland. The Annals of Inisfallen note raids of this nature occurring in 1100, 1101, 1119, and 1124. Perhaps this was what led to Tairrdelbach mac Ruaidri Ua Conchobair to build Dún Béal Gallimhe in 1124. It was located in Clan Fergal, the territory of the O Hallorans but was supervised by Ua Conchobair's vassals, the Ua Flaithbheartaigh, who at this time were still based in their homeland of Maigh Seola.

During the summer of 1132, Conchobhair O Brian of Thomond (modern north Munster) invaded Hy-Many where he "plundered ... Maenmhagh ... [and] carried off many cows." This raid was purely of a plundering nature, yet apparently within a very short space of time, he followed it up with a full-scale assault on O Conchobair's new naval base at Dún Béal Gallimhe. The Annals of the Four Masters noted that "The castle of Bun-Gaillmhe was burned and demolished [by] a fleet of the men of Munster." The Munstermen then followed this up with a devastating raid on both Clan Fergal and Magh Seola, for the same annals note that "A great slaughter was made of the Connaughtmen by the men of Munster, wherein Conchobhar Ua Flaithbheartaigh, lord of West Connaught" was slain.

Also among the dead were "the two sons of Cathal Ua Mughroin" and Ua Taidhg "an Teaghlaigh". This is significant because the Ua Mughroin were a sept native to Hy-Many, some distance from Gallimhe which was in any case historically based in a different territory, Clann Fergal. Therefore they must have travelled some distance to be present to fight against the forces from Munster, possibly in a levy raised by Tairrdelbach himself. Ua Taidgh's nickname, An Teaghlaigh, indicates that he was of the household, or indeed the household bodyguard, of Tairrdelbach, who would of necessity have only accompanied the High King. Therefore the deaths of members of these three vassal clans, as well as his own possible presence at the battle, indicates the importance the High King attached to his "dún" on the Gallimhe. This is underlined by the fact that it was rebuilt, which can be inferred by a further attack in 1149.

The 1149 siege of Dún Béal Gallimhe was led by Toirdhealbhach O Brían, then King of Thomond. It was a combined raid of plunder (taking the rich pickings of Maigh Seola) and military strategy (destroying the Dún).

In the years immediately prior to 1149, the respective interests of Connacht - still ruled by High King Tairrdelbach mac Ruaidri Ua Conchobair - and of Thomond had were confined to putting down rebellions and civil strife in their kingdoms, as well as maintaining their areas of interest. Ruaidri was frequently at odds with the Ó Neills in Ulster and Meath, and had a sometime antagonistic relationship with Tighernan O Rúairc, King of Brefine, which was a buffer state carved out of disputed territory between Connacht and Ulster.

Toirdhealbhach O Brían on the other hand was pre-occupied with extending his influence into Leinster (the kingdom whose rejection of tributes had led to his ancestor, Brian Boru's, death in 1014), as well as with putting down rebellion in his native Thomond and with ensuring his vassals of Munster, the MacCarthys, knew their place. Both Kings had in fact ratified a treaty at Terryglass Monastery in 1144, possibly to recognise and respect their spheres of influence.

However the following yeare Toirdhealbhach was decisively defeated by O Conchobair and his vassals at Feara Ceall in the Sliabh Bloom; O Brian had been en route to Meath to fight O Ruairc but had being intercepted by O Conchobair. O Brian was forced to return home, "without prey, without hostage, without peace, without truce." This brought O Brian and O Conchobhair into open war; O Brian struck within the same yeare with "an army into Connaught; and they carried off Ua Ceallaigh, i.e. Tadhg, son of Conchobhar, lord of Uí -Maine, and slew Ruaidhri Ua Flaithbheartaigh". The death of Ua Flaithbheartaigh indicates that an attempt may have being made on Gallimhe, but O Brian would have to wait a full four years before he reached this objective.

According to the Four Masters, in 1149 "An army was led by Toirdhealbhach Ua Briain and the men of Munster into Connaught, until they arrived at Magh Ua mBriuin; they carried off a great spoil of cattle, and demolished Dún-Gaillmhe; and Ua Lochlainn, lord of Corca-Modhruadh, was drowned in the (river) Gaillimh." Again, the mention of Magh Ua mBriuin - an alternative name for Maigh Seola - demonstrates the destruction of Gallimhe and its fleet was merely one tactic employed by O Brian. Kinsmen and vassals would only stay loyal as long as a king could deliver the goods to ensure their loyalty, hence the rich plains were plundered of their goods, food and fine cattle. It also had the additional prize of weakening O Conchobair's prime vassal in the area, Ua Flaithbheartaigh.

Ua Lochlainn was of the Corcu Mo Druad, vassals of O Brian, and strategically located across Galway Bay. Thus it is possible that that while O Brian led his army by land, Ua Lochlainn sailed across the bay and the two inflicted a sea-and-land siege of Gallimhe; this possibility is obliquely hinted at in the manner of Ua Lochlainn's death. It may even be that, contending for the lordship of Galway Bay - from which plundering raids could be made into Clan Fergal, Maigh Seola, Meadraige and Uí Fiachrach Aidhne - O Brian may have being letting Ua Lochlainn unleash himself against a prime adversary.

In a surprising turn of events, in 1151, O Brian was deposed as King of Munster by his son, Muircheartach. Muircheartach was subsequently captured "by treachery" by "Tadhg son of Diarmaid O Brian and Diarmaid Súgach O Conchobhair" and delivered to his father. However, Tadhg mac Diarmaid O Brian rose against O Brian in rebellion, with the result that "Toirdhealbhach son of Ruaidhrí O Conchobhair came with him to defend the kingship of Munster for him."!