Using network science to uncover the truth behind bloodshed, battles and conflict in the Sagas of Icelanders

The Sagas of Icelanders are prose narratives that tell the stories of the trials and tribulations of the early societies of Icelandic settlers more than a thousand years ago.

Njáls saga, one of the most extensive sagas, describes the life of Njál Thorgeirsson and his close friend, the warrior-chieftain Gunnar Hámundarson. All is harmonious until their wives become involved in a fierce feud, which escalates to major incidents of bloodshed in which scores of characters, including both Gunnar and Njál, die.

With a storyline that at first may appear more suited to the latest Game of Thrones series, the interwoven plot lines of the Sagas of lcelanders are still hotly debated by scholars as to whether they are historically true.

For the first time statistical physicists Ralph Kenna and Pádraig Mac Carron have used principles from network science to decide if the people, their relationships and their society structure could have feasibly existed.

The researchers were able to put together a social network for Gunnar, Njál and more than 500 other characters depicted in the saga, then analyse the resultant web to decide how probable it was that such a complex network of people could exist in real life.

Kenna and Mac Carron hope that by considering whether the large network of family, friends and foes is realistic, it may swing the debate over whether Gunnar and Njál did indeed exist, fight and die back in the 10th century.

"This approach brings to the fore the credibility of the societal backgrounds in the sagas.

"[Through] our physics-inspired investigations of saga society, we have focused on the totality of relationships between the characters depicted in the texts, rather than on the characters themselves, as most humanities researchers have done.

"Our investigations are an example of curiosity-driven research and demonstrate how ideas inspired from physics can help other fields of inquiry."