Depending on whether or not you gain financially or through an efficiency that makes your life easier, you may or may not be a big fan of algorithms. For some they are an intrusion into our privacy and for others they are a time-saving development, whose use has been so cleverly crafted they can affect elections and influence business and global trends. Algorithms have been around for some time and are increasingly determining our collective future. So much so that a friend joked recently that he might name his child Al—not short for Alexander, Albert or Allan, but for Algorithm. I am not aware of anyone who has named their child Google or Instagram yet, but give it time. The thing that bothers many people is the ubiquitous use of algorithms to evaluate individuals and place them into neat little social boxes, or to pass judgement on what they might do in the future. However they have also been used to help re-analyse the past. Modern mathematical techniques, used to analyse social media networks and connections, have recently allowed academics to shed new light on a centuries-old debate surrounding the Viking age in Ireland, specifically the Battle of Clontarf in 1014. There has been disagreement between historians on whether the battle was fought between the native Irish and the Vikings, or whether it was, in fact, a civil war with Vikings on both sides. Texts exist that point to both arguments. But now researchers at Coventry, Oxford and Sheffield Universities have analysed the most extensive of these medieval texts. They considered how all the Irish and Viking characters in the narrative fit together in a network, monitoring whether the interactions between them were benign or hostile. Lead author, Professor Ralph Kenna, a theoretical physicist at Coventry University, explained that analysis of all the connections within the medieval texts revealed an unintended message. Although those writing the history of the era, and specifically the Battle of Clontarf, may have had their own agenda, this modern form of analysis has allowed for a fresh interpretation—in this case that it was indeed a battle between the Irish and the Vikings. PhD student, Joseph Yose, who analysed the data, admitted that it doesn’t decisively resolve the question, but it does offer aggregate characteristics from largely biased accounts. However, the research does highlight another issue. Whilst our modern world is being created by manipulating data, it may be that our history could be rewritten using the very same process.