Experts believe rare 12th Century slate inscriptions found on a castle were probably made to protect against evil.

The dozen scratchings were uncovered during a three-week excavation at Nevern in Pembrokeshire.

Archaeologists think the stars and other designs were made by a serf, labourer or soldier some time between 1170 and 1190 when the castle was built.

They say they also give an insight into the beliefs of medieval working men....