[2] According to the Liber Landavensis, when King Tewdrig fell in battle against the Anglo-Saxons at the River Wye, it was his desire to be buried on Ynys Echni; however the soldiers were unable to get his body there.

[1] Following the Norman conquest of Wales, the Celtic foundation was rebuilt in the twelfth and thirteenth centuries, in the Early English style.

Under his stewardship, the aisles were widened, a porch added on the south side, and the tower, built of ashlar blocks, was constructed.

[2][4] A stone coffin, thought to contain the remains of Tewdrig, was first discovered when Francis Godwin was bishop in 1614; at that time it was moved to the chancel.

[2] During the renovation, the stone coffin was rediscovered under the altar, with a skeleton with the skull split by an axe blow, in the same way that Tewdrig supposedly died.