 Adomnán's "Life of Columba" records that St. Columba visited Bridei some time between 562 and 586, though little geographical detail is given.Adomnán also relates that during the visit, Columba converted a Pictish nobleman named Emchath, who was on his deathbed, his son Virolec, and their household, at a place called "Airdchartdan".The excavations, supported by radiocarbon dating, indicated that the rocky knoll at the south-west corner of the castle had been the site of an extensive fort between the 5th and 11th centuries.