Editing Brian Boru (section)

== High kingship ==
Brian, then in his 60s, spent the next decade or so of his life subjugating and accepting the submissions of the last of the lesser kingdoms and regions which had not already submitted to him. Those campaigns included two full circuits of the island in 1005 and 1006, demonstrating his determination and energy despite his age.<ref name=":4" />

Unlike some who had previously held the title, Brian intended to be High King in more than name. To accomplish that, he needed to impose his will upon the regional rulers of the only province that did not already recognise his authority, [[Ulster]]. The kingdoms of the [[northern Uí Néill]] and [[Ulaid]] were some of the most powerful in Ireland, and it took Brian considerable time and resources to subdue them.<ref name=":5">{{Cite book|last=Duffy|first=Seán|url=https://books.google.com/books?id=7vH4AwAAQBAJ&q=submission|title=Brian Boru and the Battle of Clontarf|publisher=Gill & Macmillan|year=2014|isbn=978-0-7171-6207-9|pages=26–27, 151–154|oclc=911972485|access-date=19 September 2020|archive-date=25 September 2021|archive-url=https://web.archive.org/web/20210925142838/https://books.google.com/books?id=7vH4AwAAQBAJ&q=submission|url-status=live}}</ref>

===Ulster campaigns===
Ulster's geography presented a formidable challenge. There were three main routes by which an invading army could enter the province, and all three favoured the defenders. Brian first had to find a means of getting through or around these defensive [[choke point]]s and then he had to subdue the fiercely independent regional kings of Ulster. It took Brian ten years of campaigning to achieve his goal, which, considering that he could and did call on all of the military forces of the rest of Ireland, indicates how formidable the kings of Ulster were.<ref name=":5" />

Brian received naval support throughout his northern campaigns from [[Sigtrygg Silkbeard]] of Dublin. Silkbeard was eager to enact revenge against the Ulaid for when they refused to assist him after he was forced out of his [[kingdom of Dublin]] by Brian following the Battle of Glenmama in 999, forcing Silkbeard to return to Dublin and submit to him.<ref name=":5" />{{Failed verification|date=July 2020}}

Brian was also greatly helped by the fact that two years before his first campaign in Ulster, in the year 1003, the brutal battle of Craeb Telcha had taken place between the Northern Uí Néill and the Ulaid, in which the king of the [[Branches of the Cenél nEógain|Cenél Eoghain]] and of the Uí Neill was killed and most of the Ulaid [[Royal descent|royal bloodline]] was wiped out, with the Uí Néill gaining victory. This then led to a bloody [[war of succession]] within and between the clans of the Ulaid, and together with further attacks from the Uí Néill, which led to the kingdom's being severely weakened. Brian accepted the submission of the Cenel Eoghain king in 1005 and later accepted the submission of many of the Ulaid clans at a sacred Ulaid site, Emain Macha.<ref name=":5" />

However [[Flaithbertach Ua Néill|Flaithbertaigh Ua Néill]], the new king of the Northern Uí Néill and of the Cenél Eoghan, although having already submitted to Brian, was apparently unwilling to accept fully the High King's authority, and was quite rebellious. He was known for his continued aggression towards his neighbours despite previously accepting Brian's rule. In 1005, after Brian had departed Ulster, he attempted to exert his overlordship over the Ulaid, and seemingly wanted to punish them for submitting to Brian, to which the Northern Uí Néill were vehemently opposed. He attacked the kingdom, killing several kings and princes of the Ulaid. He also took several hostages.<ref name=":5" />

This caused Brian to return in 1006 and again in 1007 to deal with Flaithbertach. On the latter occasion, he removed the hostages of the Ulaid from Flaithbertach's custody and took them into his own custody (according to the [[Annals of Inisfallen]], Brian had to take the hostages forcefully).{{citation needed|date=August 2020}} Flaithbertaigh again submitted, and also married one of Brian's daughters, Bé Binn.<ref name=":5" />

Despite this, Brian continued to be troubled by the rebellious Flaithbertaigh. In the year 1009, Flaithbertaigh blinded and then executed the [[Kings of Tír Chonaill|king of the Cenél Chonaill.]] Later that year he would also launch raids in the [[Midlands Region, Ireland|Midlands]] going as far south as the [[River Boyne]]. This led to Brian's return to Ulster yet again, this time taking hostages from the Cenél Eoghain back to his home province, finally gaining the proper submission of Flaithbertaigh.<ref name=":5" />

Flaithbertaigh would then take part in campaigns against the Cenél Chonaill, the final kingdom yet to submit to Brian, in the year 1011 alongside Brian's sons [[Murchad mac Briain|Murchad]] and [[Domhnall mac Briain|Domnall]]. However, they were unsuccessful in gaining the submission of the Cenél Chonaill. Brian then personally proceeded to lead a second invasion later that year, this time successfully subjugating and receiving the submission of the Cenél Chonaill. While Flaithbertaigh would continue attacking the Ulaid and Cenél Chonaill in late 1011 and in 1012, for the time he was no longer of any threat to Brian.<ref name=":5" />

Throughout his campaigns in the province, it was once again Brian's coordinated use of forces on land and at sea that allowed him to triumph; while the rulers of Ulster could bring the advance of Brian's army to a halt{{citation needed|date=September 2021}}, they could not prevent his fleet from attacking the shores of their kingdoms. Once Brian entered the province of Ulster, he systematically defeated each of the regional rulers who defied him, forcing them to recognise him as their overlord.

It was during this process that Brian pursued an alternative means of consolidating his control, not merely over the province of Ulster, but over Ireland as a whole. In contrast to its structure elsewhere, the [[Christianity in Ireland|Church in Ireland]] was not centred around [[diocese]]s and [[archdiocese]]s, but rather around [[monastery|monasteries]] headed by powerful abbots who were members of the royal dynasties of the lands in which their monasteries resided. Among the most important monasteries was [[Armagh]], located in the Province of Ulster.

Brian's advisor, [[Maelsuthain O'Carroll]], documented in the ''[[Book of Armagh]]''{{dubious|date=September 2024}} that, in the year 1005, Brian donated 22 ounces of gold to this monastery and declared that Armagh was the religious capital of Ireland, to which all other monasteries should send the funds they collected. This was a clever move, for the supremacy of the monastery of Armagh would last only so long as Brian remained the High King. Therefore, it was in the interest of Armagh to support Brian with all their wealth and power.

Brian is not referred to in the passage from the ''[[Book of Armagh]]''{{dubious|date=September 2024}} as the {{lang|mga|Ard Rí}}—that is, High King—but rather he is declared {{lang|la|Imperator Scotorum}}, 'Emperor of the Gaels'.<ref>{{cite web| url = https://www.tcd.ie/news_events/articles/crowning-of-irelands-last-scottish-high-king/| url-status = dead| archive-url = https://web.archive.org/web/20191031062115/https://www.tcd.ie/news_events/articles/crowning-of-irelands-last-scottish-high-king/| archive-date = 2019-10-31| title = Crowning of Ireland's Last, Scottish High King - Trinity News and Events}} {{Webarchive|url=https://web.archive.org/web/20201112025128/https://www.tcd.ie/news_events/articles/crowning-of-irelands-last-scottish-high-king/ |date=12 November 2020 }}</ref>

Though it is only speculation, it has been suggested that Brian and the Church in Ireland were together seeking to establish a new form of kingship in Ireland, one that was modelled after the kingships of England and France, in which there were no lesser ranks of regional kings—simply one king who had (or sought to have) power over all others in a [[unitary state]]. In any case, whether as high king or emperor, by 1011 all of the regional rulers in Ireland acknowledged Brian's authority. No sooner had Brian achieved this before it was lost again.{{Citation needed|date=August 2022}}

===Rebellion in Leinster===

[[Máel Mórda mac Murchada]] of [[Leinster]] had only accepted Brian's authority grudgingly, and in 1012 he rose in rebellion. The ''[[Cogadh Gaedhil re Gallaibh]]'' relates a story in which one of Brian's sons insults Máel Mórda, which leads him to declare his independence from Brian's authority and attack his neighbours.

Another possible reason was that the kings of Leinster and Dublin believed Maél Sechnaill was weak and that [[Kingdom of Meath|the Kingdom of Meath]] was vulnerable. This was because [[Flaithbertach Ua Néill|Flaithbertaigh Uí Néill]], king of the Cenél Eoghain and the northern Uí Néill, was again becoming troublesome for Brian. In 1013, he raided the [[Midlands Region, Ireland|Midlands]], bringing him into direct conflict with Maél Sechnaill who was the [[List of kings of Meath|king of Meath]]. The two armies had a stand-off near [[Kells, County Meath|Kells]], but Maél Sechnaill retreated for unknown reasons before any battle could occur. This led to the belief in Leinster that Meath was vulnerable, which would also weaken Brian if Leinster could knock one of his allies out of any conflict.<ref name=":5" />

Whatever the actual reason was, Máel Mórda sought allies with which to defy the High King. He found one in Flaithbertach Uí Neill in Ulster who had only recently submitted to Brian. Together, they attacked the [[Kingdom of Meath|province of Meath]] (again), where the former High King Máel Sechnaill sought Brian's help to defend his kingdom.<ref name=":5" />

In 1013, Brian led a force from his own province of Munster and from southern Connacht into Leinster, and a detachment under his son, [[Murchad mac Briain|Murchad]], ravaged the southern half of the province of Leinster for three months. The forces under Murchad and Brian were reunited on 9 September outside the walls of Dublin. The city was [[blockade]]d by Brian's fleet, but it was the High King's army that ran out of supplies first, so that Brian was forced to abandon the siege and return to Munster around [[Christmas]].

===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"/>