Editing Brian Boru (section)

==Historical view==
{{see also|Brjáns saga|Njáls saga|Þorsteins saga Síðu-Hallssonar|Cogad Gáedel re Gallaib}}
[[File:Brain Boru sculpture outside Chapel Royal outside Dublin Castle.JPG|thumb|Sculpture outside Chapel Royal.]]
For the last 250 years there has been a debate among historians about Ireland's Viking age and the [[Battle of Clontarf]]. The standard, and "popular", view, is that the battle ended a war between the Irish and Vikings by which Brian Boru broke Viking power in Ireland. However, revisionist historians see it as an Irish civil war in which Brian Boru's Munster and its allies defeated Leinster and Dublin, and that there were Vikings fighting on both sides.<ref name="RTE 2018">"Network science shines new light on Battle of Clontarf". RTE. 24 January 2018. Retrieved 24 January 2018.</ref><ref name="Kevin O 2018">Kevin O'Sullivan (24 January 2018). "Battle of Clontarf: It's a mathematical question". The Irish Times. Retrieved 24 January 2018. Centuries-old debate continues as social media analysis used to explore Viking-Irish strife ... The debate has carried on for the past 250 years.</ref> In January 2018 researchers from the Universities of Coventry, Oxford and Sheffield, led by Coventry University professor Ralph Kenna, a theoretical physicist, published a paper<ref name="royalsocietypublishing.org"/> in the journal ''Royal Society Open Science'' that used network science to mathematically analyse the 12th-century ''Cogadh Gáedhel re Gallaibh'' ("The War of the Gaels with the Foreigners", i.e. the Danes and other Norsemen), that listed over 1000 relationships between about 300 characters, and concluded that the standard and popular view of the war between the Irish and Germanic Norsemen was broadly correct, but that the picture was nevertheless more complex than "a fully 'clear-cut' Irish versus Viking conflict".<ref name="RTE 2018"/><ref name="Kevin O 2018"/> However one of the paper's co-authors,<ref>Yose, Joseph; Kenna, Ralph; MacCarron, Máirín; MacCarron, Pádraig (2018). "Network analysis of the Viking Age in Ireland as portrayed in Cogadh Gaedhel re Gallaibh". Royal Society Open Science. 5 (1): 171024. doi:10.1098/rsos.171024. PMC 5792891. {{PMID|29410814}}. This delivers a picture that lies between antipodal traditional and revisionist extremes; hostilities recorded in the text are mostly between Irish and Viking—but internal conflict forms a significant proportion of the negative interactions too.</ref> PhD student Joseph Yose, added that "Our statistical analysis ... cannot decisively resolve the debate".<ref name="Kevin O 2018"/>

The revisionist theory is that the popular image of Brian—the ruler who managed to unify the regional leaders of [[Ireland]] so as to free the land from a 'Danish' ([[Viking]]) occupation—originates from the powerful influence of the ''Cogadh Gaedhil re Gallaibh'', in which Brian takes the leading role. This work is thought to have been commissioned by Brian's great-grandson [[Muirchertach Ua Briain]] as a means of justifying the Ua Briain claim to the High Kingship, a title upon which the Uí Neill had had a near-monopoly. Recent research has suggested that it might have been commissioned by Muirchertach's contemporary and cousin, Brian Glinne Maidhir, or at least someone favourable to the line descended from Brian's son, Donnchad.<ref>{{Cite journal|last=Casey|first=Denis|year=2013|title=A reconsideration of the authorship and transmission of Cogadh Gaedhel re Gallaibh.|jstor=42751271|journal=Proceedings of the Royal Irish Academy, Section C|volume=113C|pages=139–61|doi=10.1353/ria.2013.0011|s2cid=245845422}}</ref>

The influence of this book on both scholarly and popular authors cannot be exaggerated. Until the 1970s most scholarly writing concerning the Vikings' activities in Ireland, as well as the career of Brian Boru, accepted the claims of ''Cogadh Gaedhil re Gallaibh'' at face value.

While Brian may not have freed Ireland from a Norse ([[Vikings|Viking]]) occupation, simply because it was never entirely conquered by the Vikings, his rule saw consistent conflict against Vikings and Viking-founded settlements, the latter all having been founded to give raiders easier access to the interior of Ireland. In the last decade of the 8th century, Norse raiders began attacking targets in Ireland and, beginning in the mid-9th century, these raiders established the fortified camps that later grew into Ireland's first cities: [[Dublin]], [[Limerick]], [[Waterford]], [[Wexford]], and [[Cork (city)|Cork]]. Within only a few generations, some Norse had converted to Christianity, intermarried with the Irish, and had often adopted the Irish language, dress and customs, thus becoming what historians refer to as the Hiberno-Norse.<ref name="Campbell2013">{{cite book|last=Campbell|first=Kenneth L.|title=Ireland's History: Prehistory to the Present|url=https://books.google.com/books?id=EaBOAQAAQBAJ&pg=PT46|date=5 December 2013|publisher=Bloomsbury Publishing|isbn=978-1-4725-6784-0|pages=46–51}}</ref>

Such Hiberno-Norse cities occupied a tenuous position within Ireland's political scene long before the birth of Brian. They often suffered attacks from Irish rulers, and made alliances with others. The Norse, who initially attacked and subsequently settled in Ireland, were partially assimilated by the Irish.<ref name=":4">{{Cite book|last=Newman |first=Roger Chatterton |title=Brian Boru: King of Ireland |location=Dublin |publisher=Anvil Books |year=1983|page=92|isbn=978-1-85635-719-7 }}</ref> However, Brian's father was likely slain by the Norse of Limerick and he himself died during a revolt that was supported by multiple Viking leaders, specifically the Norse of Mann.