Tadc (d. 1023), son of Brian Bórama (qv) and Echrad, daughter of Carlus mac Ailella of Uí Aeda Odba. The Uí Aeda Odba (possibly located within Southern Uí Néill territory, not far from Dublin) were the most politically insignificant dynasty that Brian married into, if indeed Echrad was a formal wife of his; theirs may have been a temporary or casual relationship. Its lower status vis-à-vis Brian’s other relationships is suggested by the Uí Aeda Odba’s obscurity and the absence of Echrad’s obituary in the annals, in contrast to those of two of his wives, Gormlaith (qv) (rigan Muman, ‘queen of Munster’) and Dub Choblaig (ben Briain, ‘wife of Brian’).
Tadc is a largely undocumented figure but nonetheless significant as the progenitor of the most successful line of Brian’s descendants, among whom were kings of Munster, Dublin, the Isles and Ireland in the eleventh and twelfth centuries, and subsequent lords and earls of Thomond in the later middle ages and early modern era.
The Banshenchas (‘Lore of women’) records that Tadc married Mór, daughter of Gilla-Brigte Ua Maíl Muaid, king of Cenél Fiachach, a union that his father would have used to undermine Máel-Sechnaill's hegemony over the midlands, by allying with a kingdom bordering on Munster and who were at odds with Máel-Sechnaill (although subsequently Tadc’s in-laws played no part in Brian’s final battle). Tadc and Mór had a son, Tairdelbach ua Briain (qv), whose reported age at death (seventy-seven in 1086) suggests that they were married by c.1009. Even if Tadc was then in his early teens, he must have been born in the middle of the 990s at the latest, rendering him at least twenty when the Battle of Clontarf (1014) occurred; clearly old enough to play a role but not recorded doing so in contemporary sources. If his half-brother Donnchad’s (qv) absence from the action is taken to suggest that Brian had misgivings about his capabilities, then the same yardstick ought to be applied to Tadc.
Only two events are recorded in Tadc’s ten-year career prior to his murder in 1023. He defeated his brother Donnchad in battle in 1014 and the following year he may have joined with Donnchad to successfully defend Limerick against Domnall son of Dub dá Bairenn of the Eóganacht of south Munster (Uí Echach). His involvement in the latter event is only recorded in the Clonmacnoise Group of annals, which consistently portrayed Donnchad in a negative light over the course of his fifty-year career; the unrelated Annals of Inisfallen from Munster, the northern Annals of Ulster and Annals of Loch Cé ascribe victory to Donnchad alone. Speculation that Tadc was behind a subsequent assassination attempt on Donnchad in 1019 (Ryan, 1941) seems little more than an attempt to supply a reason for Tadc’s murder in 1023 at the hands of the Éile (north Tipperary). In keeping with the above pattern, the Clonmacnoise Group of annals ascribe his killing to Donnchad’s influence, while the other annals do not.
Nonetheless, Tadc’s death is blamed on Donnchad in at least two bardic poems of the later middle ages. In the fourteenth century, Gofraidh Fionn Ó Dálaigh’s (qv) ‘Furigh go fóill a Éire’ (‘Patience a while, O Éire!’) depicts Donnchad murdering his brother to prevent a prophecy that Tadc would succeed Brian as high king, but ultimately being thwarted because the kingship passed instead to Tadc’s son, Tairdelbach. This motif was reused by Tadhg Dall Ó hUiginn (qv) in the second half of the sixteenth century, in ‘Ísligh do mheanma, a Mhaoilir’ (‘Subdue thine arrogant spirit, Myler’). In both poems, the poet used the motif to claim that predestined greatness would come to a son, whose career would surpass that of his father.
Despite the theory that the famous account of the battle of Clontarf Cogadh Gáedhel re Gallaibh (‘The war of the Irish with the Foreigners’) was produced under the patronage of Tadc’s grandson, Muirchertach Ua Briain (qv), Tadc is nonetheless absent from it, rather it is his half-brother, Donnchad, who features most prominently (Casey, 2020). Among the later prose texts that offer accounts of the battle, Tadc is entirely absent from Geoffrey Keating’s (qv) influential history Foras Feasa ar Éirinn (‘History of Ireland’), while his presence in the modern Irish accounts of the battle (all ultimately dependent upon Cogadh) do not possess much historical credibility. In the modern Irish Cath Cluana Tarbh (‘Battle of Clontarf’) he is included in a roll-call of one of the Munster battalions (but he is given no active part in the battle), and in its aftermath he is named with Donnchad as one of the leaders of the survivors, but again has no active role. Overall his presence in the later texts seems superfluous; inclusions by an author who may have had access to an older list of participants, such as that found in the fourteenth-century Rawlinson B 486, but who possessed no genuine information and lacked a narrative purpose for him. Likewise, the so-called Leabhar Oiris (‘Book of Chronicles’) implies that Tadc was present in the vicinity of Clontarf, but he is only mentioned briefly in the aftermath of the battle, and in the annalistic section that concludes that narrative. Nonetheless, a thirteenth-century Norse text, Brennu-Njáls saga (‘The story of Burnt Njáll’), places Tadc at Brian’s side when he was killed at Clontarf (in a role somewhere between that occupied by the servant Latean in Cogadh and Brian’s nephew Conaing in the Annals of Loch Cé). In a scene that emphasises Brian’s holiness, Tadc’s arm is severed while attempting to protect his father from attack and the blood that flowed from Brian’s wounds miraculously healed Tadc (an incident that may vaguely have been inspired by Donnchad mac Briain’s loss of his right hand in the failed assassination attempt of 1019).
In life Tadc seems to have played second-fiddle to his brother Donnchad, who established himself as king of Munster in the decade after Clontarf. Tadc’s legacy – as the bardic poets rightly noted – was as an ancestor figure whose descendants would subsequently become kings of Ireland and later lords of Thomond.