 By the eighth century, Saint Fugillus was Bishop of Clondalkin and noted gospel manuscripts were produced – the most famous of these being the Clondalkin mass book which is on display in Karlsruhe, Germany.Clondalkin was sacked by Vikings in 832 AD, and the monastery was burned to the ground.One of the early Norse kings of Dublin, Amlaíb Conung, built a fortress on the site in the middle of the 9th century.