This Church is very old and is supposed to have been used in the time of Maelgwyn Gwynedd. It is situated on the west side of Bryn Maelgwyn in Llanrhos. It is adorned with a painted window on the East Gable; the original was a gift of Hywel Ab Tudor of Mostyn and the fragments of this are believed to be preserved. The window on the South Aisle has three figures with an inscription beneath, 'Mary Bridget Mostyn, A.D. 1853'. The Transept Window on the south, which belongs to Gloddaeth, is decorated with five figures representing the Nativity, Crucifixion, Resurrection, Angels with a Harp, an inscription across, 'Glory to God in the Highest', and another with angels holding the Crown of Thorns. Below this window is the burial place of the family. The North Transept belong to Marl.
The Parish Church of St. Hilary's in Llanrhos is supposed to have existed here in the 6th Century when Maelgwyn Gwynedd was King of North Wales and had his Royal Residence at Deganwy. Tradition states that his death occurred in this Church in A.D. 666 to the Altar of which he had fled in the vain hope of escaping yellow pestilence.
Under the South Transept of Llanrhos Church are the Vaults of the Mostyn Family. In the Churchyard are tombstones of the Pugh's of Penrhyn dated 1650 and 1656.
[From a glass negative]
Original Index No. F0058.