Mac Murchada, Diarmait (MacMurrough, Dermot) (d. 1171), Gaelic lord, was the son of Donnchad who was himself the son of Murchad (qv) (a son of Diarmait (qv) son of Donnchad Máel na mBó (qv)) from whom the family name ‘Mac Murchada’ derived.
Family His mother was Órlaith, daughter of Gilla Míchíl of Uí Bráenáin. He was fostered with another Leinster family, Uí Cháellaide, with whom he retained close connections. His own marital unions were also Leinster-based. His first wife was Sadb, daughter of Cerball son of Fáelán of Uí Fháeláin, their marriage about 1132 bearing witness to Mac Murchada's attempts to move northwards beyond his own Uí Chennselaig heartland, as Marie Therese Flanagan has suggested. Of their two known children, Órlaith was given in marriage about 1168 to Domnall Mór Ua Briain (qv) who proved a useful ally to her father, particularly in his struggles against the Osraige. The latter were responsible for the death of Órlaith's brother, Donnchad, when precisely is not known. Conchobar, Diarmait's son by Mór, daughter of Muirchertach Ua Tuathail (qv) of Uí Muiredaig, whom he married about 1152, was also slain; a hostage in the keeping of Ruaidrí Ua Conchobair (qv), he was murdered in 1170 after his father had invaded Mide. His sister, Diarmait's daughter by Mór, was Aífe (qv), who was bequeathed by her father to Richard fitz Gilbert de Clare (qv) (Strongbow).
Three further children of Diarmait's have been recorded, though their maternal ancestry is not known: Domnall Cáemánach Mac Murchada (qv) who may have succeeded him as king of Uí Chennselaig for a short period; he died in 1175. Another son, Énna, was also politically active, witnessing a charter of his father's in 1162. He was captured in 1166 and blinded by Donnchad (qv), son of Gilla Pátraic of Osraige, two years later, in an attempt to halt a resurgence of Diarmait's power. A daughter, Derbfhorgaill, was married to a king of Uí Dúnchada of northern Leinster. Derbfhorgaill shares her name with the woman with whom Diarmait is most notoriously associated, Derbfhorgaill (qv), wife of Tigernán Ua Ruairc (qv), whose abduction by Diarmait in 1152 is explained in the seventeenth-century compilation, the Annals of Clonmacnoise, as being ‘to satisfie his insatiable, carnall and adulterous lust’.
Abductions and military campaigns, 1132–52 It is his lust for power that is most apparent in annalistic sources, though it is likewise as abductor that he makes his first appearance therein. In 1132 he carried off the abbess of Kildare, on which occasion her monastery was burned and 140 (or 170) were slain. This may have been his first act as king of Leinster, if the reign of 40 years attributed to him in the Book of Ballymote is correct; the more partisan Book of Leinster accords him a somewhat longer reign of 46 years. The confusion may indicate that his kingship was contested and a rival claimant, Máel-Sechnaill Mac Murchada, existed, as Donnchadh Ó Corráin has noted. His slaying in 1133 by Diarmait's loyal ally, Augaire Ua Tuathail, may have quelled internal opposition to Diarmait's rule; in any event in the following years he was in a position to expand his power beyond his home territory. Neighbouring Osraige was first to bear the brunt of his ambition; withstanding Diarmait on one occasion in 1134, they and their Waterford allies, aided by Conchobar Ua Briain (qv), king of Tuadmumu (Thomond), according to some sources, were defeated by him in another attack later in the same year. Diarmait may have had the assistance of the Dublin Norse, indicating come measure of control over the Ostmen; indeed the Annals of Clonmacnoise accord him the title ‘king of the Danes and Leinster’ on a raid into Mide in 1136. The Dubliners were at his side once more against their Waterford kinsmen the following year, in which encounter he could also draw on the support of the Thomond king who subsequently submitted to him.
Diarmait's power was far from secure, however, and Seán Duffy suggests that another attack by the Dubliners on Waterford in 1140, this time acting independently, ‘may be evidence of Mac Murchada's slackening control’. In an attempt to assert his authority he had seventeen Leinster noblemen blinded and killed the following year. Efforts to extend his supremacy further brought him into contact with his increasingly powerful contemporaries against whom he could not always compete. In 1149 he submitted to the northern ruler, Muirchertach Mac Lochlainn (qv) in Dublin; two years later, he was an ally of Tairdelbach Ua Conchobair (qv), king of Connacht, in the battle of Móin Mór. Both leaders may also have been involved in the infamous excursion into Mide in 1152 in which Derbfhorgaill's abduction by Diarmait took place. The daughter of Murchad Ua Máelshechlainn (qv), she may well have been used as a political pawn in the struggles of her brother, Máel-Sechnaill, ruler of Mide, against her husband, Tigernán Ua Ruairc of Bréifne, whose attempts to expand eastwards into Mide had long been observed. Whether Mac Murchada's acquisition of Derbfhorgaill brought him some measure of control in Mide is another matter; if so, it would have been with the agreement of Mac Lochlainn who was to become his most powerful patron in the succeeding years.
The struggle for Dublin, 1156–66 In 1156 Mac Lochlainn took Diarmait's hostages, bestowing Leinster upon him in return. This may also have included Dublin, since the Ostmen fought alongside the men of Leinster and Mide against Ua Ruairc the following year. Furthermore, his power there was deemed considerable, a contemporary annalist recording his plundering of the Hiberno-Norse inhabitants in 1162 and his subsequent assumption of nert mór . . . forro (‘great power . . . over them’), amail na rogabhadh reimhe o cein mhóir (‘such as was not obtained before for a long time’) (AU). His independence was such that he could grant land within Fine Gall to his foster-kinsman and spiritual confessor, Bishop Áed Ua Cáellaide (qv) and he is termed rex Dubliniae (king of Dublin) in the contemporary charter. A further indication of his power may be the accession of his brother-in-law, Lorcán Ua Tuathail (qv), to the archbishopric of Dublin also in 1162.
Not surprisingly, there were other pretenders to the Dublin throne, one of whom, Ruaidrí Ua Conchobair, along with his allies Tigernán Ua Ruairc and Diarmait Ua Máelshechlainn, forcibly wrested control from Mac Murchada in 1166 co tucsat Gaill rige do Ruaidhri ocus co tucsan da fiched cét bó do Gallaib (‘and the Ostmen bestowed the kingship upon Ruaidrí and the latter bestowed 4,000 cows upon the Ostmen’) (A. Tig.). Forced to flee, Diarmait burned his own stronghold Ferns rather than surrender it to his enemies, pragmatically offering hostages to the Connacht king in the process. The assassination of his key ally, Mac Lochlainn, in the same year left him isolated. Taking advantage of his precarious situation, enemies closer to home attacked, Laigin ocus Goill do impodh for Mac Murchadha ’na chintaib fein (‘Leinstermen and Ostmen turning against Mac Murchada because of his own misdeeds’), in the words of the Tigernach annalist, clearly unsympathetic to his cause. In defensive mode, he murdered the hostages of Uí Fháeláin and Uí Fháilgi, perhaps in retaliation for their proffering of hostages to Diarmait Ua Máelshechlainn. It was to no avail: Ua Máelshechlainn, together with Ua Ruairc and Mac Murchada's erstwhile subjects, the Dublin Norse, do dighail mna Huí Ruairc fair (‘to take vengeance on him for Ua Ruairc's wife’), according to the same chronicler, in an obvious reference to his abduction of Derbfhorgaill fourteen years previously, demolished his stone house at Ferns, destroying the settlement. Furthermore, they banished the Leinster ruler across the sea.
Alliance with the Cambro-Normans, 1167–71 The relative ease of his subsequent journey first to Bristol and then to Acquitaine where he received an audience from Henry II (qv) suggests that Mac Murchada already had contacts overseas. In this regard, the inclusion of a Dublin fleet, then under Diarmait's control, in a campaign against Wales led by the English king the previous year should be noted, being indicative of at least an indirect relationship between the two men. Whatever the precise reason, his plea for assistance bore fruit, his relationship with Strongbow dating to this time. However, this earl of Pembroke was not among socraidi Gall ocus Saxanach ocus ridiredh (‘the host of foreigners, Saxons and knights’) who accompanied a revitalised Mac Murchada on his journey back to Ireland in August 1167 exactly a year after his enforced exile (A.Tig.). Notwithstanding these reinforcements, the Leinster king was unable to withstand an attack by Ruaidrí Ua Conchobair assisted by his usual allies, Ua Ruairc, Ua Máelshechlainn and the Dublin Norse, co tanic Mac Murcadha a teach ríg Erenn (‘and Mac Murchada submitted to the king of Ireland [Ua Conchobair]’), giving Uí Chennselaig hostages to him and paying 100 ounces of gold to Ua Ruairc i llógh a mna (‘in compensation for his wife’) (A.Tig.).
His position improved on the arrival of a greater contingent of Cambro-Normans two years later and particularly after Strongbow entered the scene in 1170. An attack on Osraige by Mac Murchada and his foreign allies in 1169 may have served as retaliation for the blinding of his son, Énna, by Donnchad son of Gilla Pátraic the previous year. In 1170, Waterford and Wexford having been captured by Strongbow and Robert fitz Stephen (qv), Mac Murchada conquered Dublin with their assistance before plundering the territories of old enemies, Uí Fháeláin and Osraige, once more. Ambitious as ever, he marched further into Mide where Diarmait Ua Máelshechlainn's successor, Domnall Brégach, submitted to him: he had regained the pinnacle of his previous power, as Thomas Charles-Edwards has shown (‘Ireland’, 9). Predictably, Ua Conchobair reacted, slaying Uí Chennselaig hostages, including Mac Murchada's son, Conchobar, who as rígdamna Lagen ‘heir-apparent of Leinster’ was one of his possible successors. The question of the succession was soon to become an issue since Diarmait died in 1171 iar cind bliadne do galar etualaing (‘after a year of insufferable illness’) (A.Tig.).
Succession and reputation According to Irish sources, his son, Domnall Cáemánach, brother Murchad (qv), as well as the latter's son Muirchertach, succeeded him, since all three are termed kings of Uí Chennselaig in the Book of Leinster king-lists. In addition, Diarmait's son, who died a mere four years after his father, is termed rí Laigen (king of Leinster) in his obituary in the Annals of Tigernach. By contrast, the kingship of Leinster, at Diarmait's explicit request, went to Strongbow after his death, according to Gerald of Wales (qv) in his late twelfth-century work, Expugnatio Hibernica (The Conquest of Ireland) and this is corroborated in ‘The Song of Dermot and the Earl’, a narrative poem in Old French, written in the last decade of the same century. As part of the marriage settlement for Diarmait's daughter, Aífe, this unusual bequest has been much debated. As a literary trope, it is not unique: the Hiberno-Norse king of Dublin, Sitriuc Silkbeard (qv), offered the hand of his mother Gormlaith (qv) (d. 1030) in marriage, as well as the kingship of Ireland, to Earl Sigur of Orkney, according to the Icelandic tale, Brennu-Njáls saga (The Saga of Burnt Njáll), which may well date to about the same time. Historical considerations may also underlie the claim, and Charles-Edwards's suggestion that it was the kingship of Dublin which was in fact offered to Strongbow has much to commend it, Diarmait's action being in keeping with that of a number of previous rulers who had placed key allies, usually sons, in control of Ireland's primary town. Strongbow was not to attain this pivotal position since Henry II made himself lord of Dublin and of the other coastal settlements, Wexford and Waterford. However, since he continued to hold lands in Leinster under the English king, Strongbow came to be seen as Mac Murchada's heir in that territory. That the latter should have offered his son-in-law his entire kingdom, rather than Dublin alone, might readily have been claimed (Charles-Edwards, ‘Ireland’, 26–34).
Whatever the exact nature of Mac Murchada's agreement with Strongbow, it is this and his association with Cambro-Normans more generally that has retrospectively defined the career of one who came to be known as Diarmait na nGall (of the foreigners). Described in his obituary in the Annals of Tigernach as fer buaidhirtha na Banba ocus aidhmillti Erenn (the disturber and the destroyer of Ireland), it is his mustering of foreigners which soon came to be specifically condemned. Among some of those foreigners at least, his reputation was equally abysmal, Gerald of Wales, who came to Ireland in 1185 with Henry II's son, John (qv ), regarding him as a grievous tyrant. By contrast, the anonymous author of ‘The Song of Dermot and the Earl’ presents him in heroic terms, the noble ancestor of the English in Leinster, the legitimacy of whose occupation the poet was anxious to underline. Irish authors also applauded him, a marginal note in the Book of Leinster written on his banishment bemoaning the deed, uch uch a Chomdiu cid dogen (alas, alas, o Lord, what will I do). His death iar mbúaid ongtha ocus athirgi (after the victory of extreme unction and penance), is recorded elsewhere in the same manuscript and he is hailed as aird-rig Laigen 7 Gall 7 urmor Erend uile (high-king of Leinster and the Ostmen, as well as of the greater part of Ireland) in the Banshenchas (women-lore). His generous endowment of churches and fame as a patron of reform endeared him in certain quarters, a Cistercian abbey at Baltinglass and a Benedictine abbey at Kilkenny being among his foundations. The negative image of him was ultimately to prevail, however, Mac Murchada coming to personify, in the words of a Classical Irish poet, in diabhal dúr (the dour devil).