# Modern math sheds new light on long-standing debate about Viking-age Ireland conflict

Modern mathematical techniques - similar to those used to analyse social-networking websites - have allowed academics to shed new light on a centuries old debate surrounding the Viking age in Ireland and the famous battle of Clontarf in 1014.

The widespread view among the public is that the battle was the climax of a war between the Irish and Vikings at which, under Brian Boru's leadership, Irish victory finally broke Viking power in Ireland.

However, revisionist historians have long since challenged this view believing, instead, it was a conflict between opposing Irish sides with Munster and its allies victorious over Leinster and Dublin, and Viking warriors on each side.

The debate about the conflict has lasted at least 250 years and medieval texts have been used by both sides to support their cases.

But now researchers at Coventry, Oxford and Sheffield Universities have analysed the most extensive of these medieval texts using a mathematical approach similar to that used to analyse the connections between people on , such as Facebook.

Their findings, published today in the journal Royal Society Open Science, support the long-standing popular view that the Battle of Clontarf was the climax of a war mainly between the Irish and Vikings. This is contrary to the revisionist view that it was an Irish civil war.

To perform the study, the academics analysed how all the Irish and Viking characters in the fit together in a network, monitoring whether the interactions between them were benign or hostile.

They developed a mathematical measure to quantify whether hostility in the network mainly connected Irish to Irish or Irish to Vikings.

They then calculated the difference between the measure of hostilities between each type of character (Irish and Viking) and what would have been hostile interactions in the network, indiscriminate of whether characters were Irish or Viking.

A positive value of the resulting measure would signal Irish civil war and a negative number would reflect an Irish versus Viking conflict. The results gave an overall negative value suggesting that the text mainly describes an Irish against Viking conflict.

However, because the negative value was moderate (-0.32 on a scale from -088 to 1) they suggest the text does not describe a fully "clear-cut" Irish versus Viking conflict. Instead, the network portrays a complex picture of relationships and social networks of the time.

Lead author Professor Ralph Kenna, a theoretical physicist at Coventry University, said:

"Every school child in Ireland is taught about the battle of Clontarf; it's an iconic event in our country's history.

"We've used science to give a greater understanding of medieval accounts and to give new insight into the relationships and hostilities from this period, a topic that has been argued about for hundreds of years.

"The medieval composer of the text certainly did not think in terms of social networks but, in recording a cast of hundreds with well over a thousand connections between them, he imprinted them into the narrative.

"This is why the networks approach delivers unique new insights; it extracts an unintended message. The paper goes beyond previous works in that it generates a new quantitative element to the complexity and conflicts of a long-standing debate about the Viking age in Ireland."

PhD student Joseph Yose, who analysed the data, said:

"There are no detailed independent historical records of the time and the data come from a skilfully written medieval text replete with bias, exaggerating virtues and vices of many of its characters.

"Our statistical analysis delivers aggregate characteristics, largely insensitive to such individual and rhetorical elements. While it cannot decisively resolve the debate, we hope it delivers useful statistical information on the Viking Age in Ireland."

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Science sheds light on 250-year-old literary controversy

More information: Network Analysis of the Viking Age in Ireland as portrayed in Cogadh Gaedhel re Gallaibh, Royal Society Open Science, rsos.royalsocietypublishing.or … /10.1098/rsos.171024
Journal information: Royal Society Open Science

Feedback to editors

Jan 23, 2018
I can see all sorts of things that could yield to this sort of analysis. A specific thing that springs to mind are the middle age plagues. These events were also documented by many writers from many different viewpoints and contexts. Being able to trace in much finer detail how the disease spread at more precise time tables would assist in the current debate over flea/rodent causation.

Jan 23, 2018
Revisionism is just one more example of "right-speak." You can already go to jail in Europe (Western) for saying certain things, the whole place might as well be under the old Soviet flag.

Jan 24, 2018
The main problem here is that the texts themselves are fundamentally flawed, selective and biased already, so merely 'mapping them out', to put it bluntly, doesn't solve that problem.

@Thorium Boy: I really shouldn't bother responding to you, but revisionism is a long-standing concept in historiography and, contrary to what ignoramuses like you seem to think, it is a neutral term to describe interpretations that challenge received wisdom. For instance, the view that the French Revolution laid the foundation for modern democratic Europe, the dominant view among historians nowadays, was originally (in the 19th century) a revisionist challenge to the dominant view that it was a temporary disturbance in the process of enlightened rule by benevolent oligarchies and enlightened autocrats.

Your hysterical claims about being jailed are stupid beyond belief. You do realize that slander and inciting violence are also examples of "going to jail for saying certain things", right?

Jan 24, 2018
So TB... We meet again, sir.

If I correctly understand your contention?

Radical Muslims and gullible teenagers are being ''persecuted' for 'speaking out' against the corrupt, decadent democratic republics of Western Europe?

Jan 26, 2018
Your hysterical claims about being jailed are stupid beyond belief. You do realize that slander and inciting violence are also examples of "going to jail for saying certain things", right?
But the Irish was so tiny back den an dey was drunk all the time. And all they had was shillelaghs so i think this has to be fake news.

Jan 26, 2018
As the sign on the mercantile establishment door read:

"No Dogs or Irish permitted entry!"

Which was total rubbish. Cause neither the dogs nor the Irish could read!