Ceneu (Kayne, or Keyna) is the name of several Welsh saints:
1. A recluse of Keynsham, commemorated Oct. 8, whose memory is greatly honored on both sides of the Severn, is said to have been the third daughter of Brychan, of Brycheiniog; but it is more probable that she was either the granddaughter of this Brychan, or the daughter of another, who lived at a later period. According to the legend, in her youth she took up her abode in a wood or desert place near Avon, where the abundance of serpents made the place uninhabitable.
But having by prayer performed the miracle of changing the serpents into stones, as is still related of her in that district, she remained for many years where Keynsham now stands, and in her old age returned to Brecknock at the request of her nephew, St. Cadoc. There she died in the 5th or beginning of the 6th century, but the place of her interment is unknown. Her name is perpetuated at St. Keyne, a parish in Cornwall; and at Keynsham, in Somerset.
2. Son of Coel, a Welsh saint of the 4th century.
3. Bishop of St. David's in the 6th century, founder of a church named Llangenen, once existing in Pembrokeshire, all traces of the situation of which were obliterated by the Flemings who settled in that county. He was the third bishop, according to one text of Giraldus Cambrensis; but, according to another, he is absent from the list.