Like many early Irish monasteries, Bangor was destroyed and rebuilt on a number of occasions. The Annals of Ulster record that Bangor was burned in 616 and again in 755. No doubt at this period the buildings were constructed of wood. Easily accessible from the sea, Bangor invited attack, and between 822 and 824 the Norsemen plundered it. The Annals of Ulster and the Four Masters both record that during this raid, “learned men and bishops” were smitten, while the shrine containing the relics of Comgall was taken. Another probable victim of the Vikings was “Tanaidhe MacUidhir, coarb of Bennchor, who was killed in 958. There is a consensus that the importance of Bangor declined around the latter part of the tenth century.