 In 842 and 851 , Canterbury suffered great loss of life during Danish raids . In 978 , Archbishop Dunstan refounded the abbey built by Augustine , and named it St Augustine 's Abbey . A second wave of Danish attacks began in 991 , and in 1011 the cathedral was burnt and Archbishop Alphege was killed in 1012 . Remembering the destruction caused by the Danes , the inhabitants of Canterbury did not resist William the Conqueror 's invasion in 1066 . William immediately ordered a wooden motte @-@ and @-@ bailey castle to be built by the Roman city wall . In the early 12th century , the castle was rebuilt with stone . 
