 The following year Cerball defeated an attack by Vikings from the Irish midlands, perhaps from Dublin, led by one Hákon.This battle is said by some sources to have taken place at "Carn Brammit", a site which can no longer be identified.The late "Annals of the Four Masters" record an invasion of Osraige in 848 by the Uí Ceinnselaig of southern Leinster, led by their king Echtigern mac Guaire.