According to a famous legend, St. David was once instructed by an angel to return to Pembrokeshire to establish a monastery. He and his friends, including St. Aidan, celebrated their arrival home by building a large fire. Unfortunately for them, the fire was on the land of a feared Irish chieftain named Boia. He and his family lived in an old fort and were infamous for terrorising the surrounding lands. Boia was furious with this intrusion on his lands, and decided to lead his best warriors out to attack them. As they approached the holy men, a strange fever came over Boia and his men. They retreated to their fort but soon discovered all of their cattle and sheep were dead. Realising the power of the intruders, Boia returned to St. David and humbly requested mercy. St. David made peace with Boia and restored his animals to life, but only after Boia donated land for the new monastery.

Boia’s wife was furious when she heard this and tried to remove St. David herself. She sent her female slaves to bathe naked, play suggestive games and use lewd words in front of the monks. The monks begged St. David to leave lest they fall to temptation, but he refused and restored order by leading the monks in fasting and praying all night.

In a final act of defiance Boia’s wife sacrificed her step-daughter Dunawd to the pagan gods. When she realised the sacrifice had done nothing, she went mad and was never seen again. Boia decided to avenge his wife and daughter and prepared to attack St. David again, but before he could another Irish chieftain invaded his land and beheaded him. Devine retribution continued; fire rained down from the sky destroying Boia’s settlement. Over 1,400 years later, when archaeologists came to excavate at Clegyr Boia, they found the charred remains of huts and storehouses.