overking in 916, and he marched into Munster against Ragnall, but no decisive engagement followed. The men of Leinster under Augaire mac Ailella attacked Sithric but suffered a heavy defeat in the Battle of Confey or Cenn Fuait (917). This victory allowed Sithric to re-establish Norse control over Dublin. Ragnall left Ireland again in 918, and became king of York. With Sithric in Dublin and Ragnall in York, a Dublin-York axis developed which would have influence on both England and Ireland for the next half-century. A new and more intensive period of Viking settlement in Ireland began in 914. Between 914 and 922 the Norse established Waterford, Cork, Dublin, Wexford and Limerick. Significant excavations in Dublin and Waterford in the 20th century have unearthed much of the Viking heritage of those cities. A large amount of Viking burial stones, called the Rathdown Slabs, have been found in multiple locations across South Dublin. The Vikings founded many other coastal towns, and after several generations of coexistence and intermarriage a group of mixed Irish and Norse ethnic background arose (often called Norse-Gaels or Hiberno-Norse). Norse influence shows in the Norse-derived names of many contemporary Irish kings (e.g. Magnus, Lochlann or Sitric), and in DNA evidence in some residents of these coastal cities to this day. A genetics paper in 2006 by Dr Brian McEvoy found that most men with Irish-Viking surnames carried typically Irish genes. This suggests that Viking settlements may have had a Scandinavian elite but with most of the inhabitants being indigenous Irish. Niall Glúndub marched on Dublin in September 919, but Sihtric met his forces at the battle of Islandbridge or Áth Cliath and inflicted on him a decisive defeat, with Niall and numerous other Irish leaders among the casualties. Dublin was secured for the Norse, and in 920 Sitric left for York and following Ragnall's death succeeded him as ruler there in 921. Their kinsman Gofraid assumed control of Dublin. Gofraid was active as a Viking raider and slaver, but there were signs during his reign that the Norse were not just mere Vikings any more. During a raid at Armagh in 921 Gofraid "...spared the prayerhouses... ...and the sick from destruction", considerations never taken by the raiders of the previous century. Another was the intense campaigns led by Dublin in eastern Ulster from 921 to 927, which appear to have aimed at conquest in order to create