The oldest parts of Capel Lligwy date from the first half of the 12th century . This was a time when many churches on Anglesey in north @-@ west Wales were first built in stone following the end of Viking raids and attempts by the Normans to gain control of the island . The reason for its construction , and the saint to whom it was dedicated , are unknown . Geraint Jones , author of a 2006 guide to the churches of Anglesey , suggests that it may originally have been a memorial chapel , or connected to a royal court nearby . Yates and Longley , authors of a 2001 guide to ancient Anglesey monuments , note that it was built in the large parish of Penrhos Lligwy and was perhaps intended to serving the expanding population in medieval times . Despite this , it seems to have remained as a chapel of ease rather than become a parish church in its own right . The chapel is sometimes referred to as " Hen Gapel Lligwy " ( " hen " being the Welsh word for " old " and " capel " meaning " chapel " ) .