In the spring of 1014 Brian Boru mustered his forces and marched on Dublin to suppress a rebellion by King Sitric Silkenbeard and Sitric’s uncle Máelmórda, king of Leinster. Sitric also recruited outside armies, including Earl Sigurd of Orkney and the commander of a Scandinavian fleet called Bródar (who was perhaps Manx), and probably Danes involved in the conquest of England by the family of King Canute. This fleet descended on Dublin Bay at Easter in 1014.

Brian initially pitched his camp on “the green of Dublin” – nobody knows exactly where this was – and sent troops to raze the Dubliners’ lands in Fingall. When Dubliners saw the area around Howth ablaze they marched north from their fortress to Mag Elta, the coastal plain north of Howth, and “raised their battle standards on high”. They were led by King Sitric’s brother Dubgall. Sitric remained in Dublin to prevent its falling into Irish hands. Then on the high tide of about 5.30am on Good Friday, the Scandinavian fleet put in somewhere near Clontarf.

The exact location of the now inevitable battle has been fiercely debated; the 12th-century Book of Leinster calls it the Battle of Clontarf Weir (Cath Corad Cluana Tarb). Some consider this a salmon weir on the River Tolka near Ballybough Bridge, but this was not part of medieval Clontarf so the weir was more likely an estuarine fish snare along the tidal shoreline at Clontarf.

This is corroborated by the Cogadh Gáedhel re Gallaibh ( The War of the Irish W ith the Vikings ), which says that Brian’s 15-year-old grandson Tairdelbach “went after the Foreigners into the sea, when the rushing tide wave struck him a blow against the weir of Clontarf” – “im carrid Cluana Tarb” – “and so he was drowned”.



1,000 mail-clad warriors

Assembling in three battalions – the Scandinavians in the van, the Dublin Norse in the middle and the Leinstermen in the rear – Brian’s enemies prepared for the ensuing struggle, having among their ranks 1,000 mail-clad warriors.

The high king’s forces were led by his son Murchad – Brian was at least 73 and does not appear to have taken part in person – and the Dál Cais army had behind it the rest of the forces of Munster, followed by contingents from Connacht and probably those of Brian’s predecessor as high king, Máel Sechnaill (although some biased accounts say that the latter refused to fight).

The battle, which began at first light, raged all day. Such was the ferocity, the Cogadh tells us, that within the length of time it takes to milk a cow nobody on either side could recognise even his own son or brother, except by voice, so covered were they in blood. Spears could not be raised above the head, so clogged did they become with hair that floated in the wind, having been hacked by swords and axes from the heads of the enemy.

And the showers of sparks from the swords of Brian’s warriors as they struck their opponents’ coats of mail were said to be visible from the fortress of Dublin.

By evening the Norse were compelled to retreat, but as the tide receded so it drew the Scandinavia vessels with it, scattering them about the bay. They would have made for the safety of a wood lying towards Howth, but the incoming tide prevented it. Similarly, on the west side of the battlefield, up to 6,000 of Brian’s enemies were slaughtered as they fled, only 20 Dubliners, the Cogadh tells us, escaping, “and it was at Dubgall’s Bridge the last of these was killed”.

The assumption that this bridge was over the Liffey (near the Four Courts) has given rise to the mistaken belief that the core battleground extended towards Oxmantown, but Dubgall’s Bridge probably straddled the Tolka at Ballybough, meaning that most of the action lay east of it.

The retreating Norse needed to cross the Tolka to escape to Dublin, but the tide now intervened. Some did make it across, and one source has it that the king of Tara, Máel Sechnaill, managed to eliminate them in skirmishes in the area between the Tolka and the Liffey.

On the modern landscape the main scene of battle was perhaps at the old heart of Clontarf – say, between Castle Avenue and Seaview Avenue/Stiles Road – Brian’s foes being pushed downhill towards the sea.

To escape to the Tolka bridge the Norse and Leinstermen would have to cross what is now Fairview Park, except that the incoming tide had submerged it. In the other direction was the protection of a wooded area that lay perhaps to the east of Vernon Avenue, but the inundation of the area around Oulton Road and Belgrove Road blocked that route also, so they had no option but to position themselves with their backs to the sea and make a stand. This was a disaster, as many drowned as they were beaten back.

Among the slain were Máelmórda of Leinster and Sigurd of Orkney – who, the Icelandic sagas tell us, died because he grabbed the magical black-raven banner his mother had made, which offered protection to those behind but not to him who carried it.

Some accounts have him dying in combat with Brian’s son and intended heir, Murchad, who also died, as did the latter’s son Tairdelbach.



Brian beheaded?

Brian too was killed, perhaps beheaded (as was his nephew Conaing), later tradition crediting the deed to Bródar, who came across the praying king while fleeing the battlefield, Njáls S aga adding the colourful detail that, when Bródar himself was apprehended, his captors “cut open his belly, and led him round and round the trunk of a tree, and so wound all his entrails out of him”.

Having had a premonition of his own death on the eve of battle, Brian had made a will instructing that his body be carried to Swords, Duleek and Louth, then brought for burial in Armagh.

This took place with considerable solemnity, although unfounded Dublin tradition later supposed that he, Murchad or both were buried at Kilmainham.