 Late in 845 the Norse chieftain Thorgest or Turgesius, who had emulated Feidlimid mac Crimthainn by attacking Clonmacnoise and Clonfert, was captured by Máel Sechnaill, and drowned in Lough Owel.Máel Sechnaill's reign was portrayed in later sources as being frequently a matter of war with the Vikings and Norse-Gaels, thanks largely to works such as the "Cogadh Gaedhil re Gallaibh", a panegyric written for Muircheartach Ua Briain, great-grandson of Brian Boru.The annals tell of frequent battles between Máel Sechnaill and the Vikings, both when they were acting on their own and as allies to Cináed mac Conaing or Cerball mac Dúnlainge.