 In the words of architectural historian John Newman, it was later "grandiosely enlarged" by John Marshall, the Bishop of Llandaff between 1478 and 1496.Under his stewardship, the aisles were widened, a porch added on the south side, and the tower, built of ashlar blocks, was constructed.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.