Editing Brian Boru (section)

===Battle of Clontarf===
{{Main|Battle of Clontarf}}
 
[[File:'Battle of Clontarf', oil on canvas painting by Hugh Frazer, 1826.jpg|300px|thumb|Oil painting of Battle of Clontarf by [[Hugh Frazer (artist)|Hugh Frazer]] 1826]]
Máel Mórda was aware that the High King would return to Dublin in 1014 to try once more to defeat him. He may have hoped that by defying Brian, he could enlist the aid of all the other regional rulers. If so, he was sorely disappointed. The province of [[Connacht]] and most of the province of [[Ulster]] failed to support either side of the conflict, with the exception of [[Flaithbertach Ua Néill]] of the northern Uí Néill who sent troops to Máel Mórda. His inability to obtain troops from any rulers in Ireland may explain why Máel Mórda sought support from rulers outside Ireland, sending his subordinate and nephew, Sigtrygg, the ruler of Dublin, overseas to do so.<ref name=":5" />

Sigtrygg sailed to [[Orkney]], and on his return stopped at the [[Isle of Man]]. These islands had been occupied by the Vikings long before and the Hiberno-Norse had close ties with Orkney and the Isle of Man. There was even a precedent for employing Norsemen from the isles; they had been used by Sigtrygg's father, [[Amlaíb Cuarán]], in 980, and by Sigtrygg himself in 990. Their incentive to fight was loot, not land.

It has been argued that, contrary to the assertions made in the ''Cogadh Gaedhil re Gallaibh'', this was not an attempt by the Vikings to reconquer Ireland. All of the Norsemen, both the [[Norse-Gaels]] of Dublin and the Norsemen from the Isles, were in the service of Máel Mórda. The High King had 'Vikings' in his army as well: the Hiberno-Norse of Limerick and probably those of Waterford, Wexford, and Cork as well. Some sources include a rival gang of Norse mercenaries from the Isle of Man, led by [[Brodir and Ospak of Man|Brodir's]] own brother, [[Brodir and Ospak of Man|Óspak]]. The two brothers would go on to fight on opposite sides in the battle. Some scholars argue that, essentially, this conflict was an Irish civil war with minor foreign participation.<ref name=McCullough109>McCullough(2002), p.109</ref> However, the revisionist idea of Brian Boru's campaign and the battle of Clontarf being more akin to a civil war than an international war between the Irish and Norsemen has recently been challenged by researchers from the Universities of Coventry, Oxford and Sheffield. Using [[Network theory|network analysis]] to mathematically analyze the medieval text, they found over 1000 relationships between about 300 characters; as such, the traditional view may be more accurate after all.<ref name="royalsocietypublishing.org2">{{Cite journal|last1=Yose|first1=Joseph|last2=Kenna|first2=Ralph|last3=MacCarron|first3=Máirín|last4=MacCarron|first4=Pádraig|year=2018|title=Network analysis of the Viking Age in Ireland as portrayed in Cogadh Gaedhel re Gallaibh|url=|journal=Royal Society Open Science|volume=5|issue=1|page=171024|doi=10.1098/rsos.171024|pmc=5792891|pmid=29410814}}</ref>

Along with whatever troops he obtained from abroad, Brian mustered troops from his home province of Munster, southern Connacht, and the province of Meath, the latter contingent commanded by his old rival Máel Sechnaill mac Domnaill. Brian's army may have outnumbered Máel Mórda's, since Brian felt secure enough to dispatch a mounted detachment under the command of his youngest son, Donnchad, to raid southern Leinster, presumably hoping to force Máel Mórda to release his contingents from there to return to defend their homes.

Brian was also joined by the aforementioned [[Brodir and Ospak of Man|Óspak]], a Norseman, brother of [[Brodir and Ospak of Man|Brodir]]. Initially the two brothers sailed from the [[Isle of Man]] to fight against Brian with the Leinster forces. However, after a disagreement, Brodir planned to kill Óspak and his men the next morning. Óspak and his soldiers then fled during the night with 10 ships and sailed around Ireland to [[Connacht]], where Óspak converted to Christianity and swore allegiance to Brian. He fought on the opposite side to his brother at the battle.<ref>Njals Saga, Chapter 144–145</ref>

Brian and Máel Sechnaill sent their forces to torch and plunder much of the countryside and hinterland north of [[Clontarf, Dublin|Clontarf]] as far as the [[Howth]] Peninsula. However, in one of their raids, one of Máel Sechnaill's sons, Flann, was killed when a raiding party he was leading was ambushed by the Norse, with a total of over 150 Irish killed.<ref name=":1">Seán Duffy, History Ireland</ref><ref>{{Cite web|last=Doherty|first=Charles|title=Maél-Sechnaill (Maél-Sechnaill II; Malachy Mór)|url=https://dib.cambridge.org/viewReadPage.do;jsessionid=30D6BEA6AD0E45096EDD595AA7533EF2?articleId=a5322|website=dib.Cambridge.org|access-date=27 June 2020|archive-date=27 June 2020|archive-url=https://web.archive.org/web/20200627192200/https://dib.cambridge.org/viewReadPage.do;jsessionid=30D6BEA6AD0E45096EDD595AA7533EF2?articleId=a5322|url-status=live}}</ref>

A disagreement between Brian and Máel Sechnaill resulted in the latter withdrawing his support. Brian sent a messenger to find Donnchad and ask him to return with his detachment, but the call for help came too late. To compound Brian's problems, Máel Mórda's Norse contingents, led by [[Sigurd Hlodvirsson]], [[Earl of Orkney]], and [[Brodir and Ospak of Man|Brodir]] of the Isle of Man, arrived on [[Palm Sunday]], 18 April. The battle occurred five days later, on [[Good Friday]], 23 April 1014, just north of the city of [[Dublin]], at [[Clontarf, Dublin|Clontarf]].<ref name=McCullough111>McCullough(2002), p. 111</ref>

[[File:07 Brian on the Morning of Clontarf.jpg|thumb|Brian on the Morning of Clontarf]]
[[File:St Patrick's (COI) Cathedral, Armagh 087.jpg|thumb|Plaque at Brian Boru's burial place in [[St Patrick's Cathedral, Armagh (Church of Ireland)|St. Patrick's Cathedral, (COI), Armagh]]]]

All of the accounts state that the [[Battle of Clontarf]] lasted all day, but this may be an exaggeration.{{original research inline|date=March 2016}} The fighting was incredibly bloody by all accounts. Brian's army, however, eventually broke the enemy line and the Vikings attempted to flee for their ships which were in the bay. However at this time the tide came in and many of them [[Drowning|drowned]] attempting to swim for their ships as they were relentlessly pursued by the Irish.<ref name="Duffy">Duffy (2013)</ref><ref>McGettigan(2013)</ref>

Brian's Irish army won partly through a small numerical advantage, and the use of small spears which they threw at the enemy. According to one account, [[Máel Sechnaill mac Domnaill|Maél Sechnaill]] had a change of heart and arrived late to the battle and, after the death of Brian, led the Irish army and completed the rout.<ref name="Duffy" />

Apart from Brian himself, much of the Irish [[Royal descent|royal bloodline]] was wiped out in the battle. The king's son and heir, [[Murchad mac Briain|Murchad]], was killed. According to one account he killed over 100 enemies, but the details of his own death are unknown. He died shortly after the Viking line broke.<ref name="Duffy"/>

Brian's grandson and Murchad's son [[Toirdelbach mac Murchada meic Briain|Toirdelbach]] was also killed. Aged 15, he led the Irish [[infantry]] pursuing the Vikings as they fled to the sea. He was knocked over by a wave, knocking him unconscious after hitting his head, and he drowned.<ref name="Duffy"/>

On the Leinster and Viking side, many were also killed. [[Máel Mórda mac Murchada|Maél Morda]] was killed in the fighting. [[Sigurd the Stout|Sigurd the Stout of Orkney]] was also killed by [[Murchad mac Briain|Murchad]]. [[Brodir and Ospak of Man|Brodir]], who likely killed Brian, was captured and executed after the battle.<ref name="Duffy"/>