Domnall mac Eimín meic Cainnig (died 23 April 1014) was an eleventh-century Mormaer of Mar. He is attested by numerous accounts of the Battle of Clontarf in which he is said to have lost his life supporting the cause of Brian Bóruma mac Cennétig, High King of Ireland, a king whose forces fought against those of Sitriuc mac Amlaíb, King of Dublin, Máel Mórda mac Murchada, King of Leinster and Sigurðr Hlǫðvisson, Earl of Orkney. Domnall is the first Mormaer of Mar on record, and the Irish sources that note him are the earliest sources to note the province of Mar. Domnall is the only Scottish combatant recorded to have in the Battle of Clontarf. His motivations for fighting are uncertain.
Attestations
Domnall may have been of Scandinavian descent. The name of his father could be a Gaelic form of the Old Norse Eyvindr. Domnall was a Mormaer of Mar. The province of Mar straddled the River Dee and River Don in Aberdeenshire. By about 1100, Mar formed one of the core provinces of the Kingdom of Alba. Domnall is the earliest mormaer from the province on record. In fact, notices of Domnall in Irish sources are the earliest record of the province itself.
The meaning of the Gaelic title (plural ) is uncertain. It could derive from elements meaning "sea steward" or "great steward". In historical sources, the title almost always has Scottish connotations. It appears to denote one of the most important royal officials—aside from the king—as a kind of steward or bailiff. In times of peace, a Scottish mormaer would have overseen one of the provinces of Alba, and in times of war, he would have commanded its military forces. By the twelfth century, the office of mormaer became territorialised, and the title became Latinised as comes, a term otherwise used for the English earl.
In 1014, Domnall fought and died at the Battle of Clontarf, supporting the cause of Brian Bóruma mac Cennétig, High King of Ireland. The battle was fought by the forces of the High King of Ireland against the allied forces of Sitriuc mac Amlaíb, King of Dublin, Máel Mórda mac Murchada, King of Leinster, and Sigurðr Hlǫðvisson, Earl of Orkney. Although Brian's forces won the fight, it was a Pyrrhic victory, leaving both sides decimated, with Brian and members of his immediate family amongst the dead, and his objective of capturing Dublin left unfulfilled.
Domnall's part in the clash is noted by numerous historical sources: including the seventeenth-century Annals of Clonmacnoise, the sixteenth-century Annals of Loch Cé, the seventeenth-century Annals of the Four Masters, the fifteenth- to sixteenth-century Annals of Ulster, the twelfth-century Chronicon Scotorum, the twelfth-century Cogad Gáedel re Gallaib, and the thirteenth-century Cottonian Annals. Another important account of the battle noting Domnall is preserved within the manuscript Oxford Bodleian Library MS Rawlinson B 486. It is remarkable that the Munster-based eleventh- to fourteenth-century Annals of Inisfallen makes no notice of Domnall.
Domnall appears to have been one of the principal commanders in the battle, and appears to have commanded a portion of Brian's army composed of foreign mercenaries. The forces of the Dublin-Leinster-Orkney coalition were commanded by Máel Mórda and Sigurðr. Brian does not appear to have taken part in battle, whilst Sitriuc's part is more obscure.
According to Cogad Gáedel re Gallaib, Brian's forces were organised into three battalions. The battalion that appears to have formed the left flank is stated to have been composed of ten mormaers and their Scandinavian allies. With exception to Domnall, the obscurity of this formation's commanders is remarkable in comparison to the other battalions. This partly evinces the probability that Domnall's unit was mainly composed of Scandinavian troops. Opposite this battalion, the coalition's right flank appears to have been composite force of Scandinavian mercenaries in the fore and Leinstermen in the rear.