West wall of St Brynach's church, Cwm-yr-Eglwys. The rest of the church was washed away by the tremendous seas generated by the Great Storm of 25-26 October 1859.
The earliest surviving document for the parish and possibly the church is the Norwich Taxation of 1254 which notes a dispensation, at the request of the cardinal of the Holy Apostles, to Maurice to hold the churches of Dinas and Nambeude, together with that of Hebernat; the value of all three not exceeding 12 marks.
A drawing by H Gastineau c 1825 is believed to show the church's final form - a nave measuring 36ft x 14ft orientated east-west, with a chancel measuring 18ft by 12ft on the eastern end, and a transept measuring 18ft x 12ft adjoin the southern wall. Above the west door, there was a bell-cote.
The architectural history preserved in the building's fabric was lost in the Great Storm of 1859. During which Cwm-yr-eglwys was exposed to the northeast and the storm's resultant surge of 15ft (4.5m) above normal high water carried away the side wall and roof.
In the Haverfordwest and Milford Haven Telegraph, Owen Edwards, Coroner to the Northern Division of Pembrokeshire, described the scene - 'the sea washing right through it. The churchyard is much injured. Several houses are damaged; one house in particular is nearly destroyed'.
To the east of the church, a schooner, the MATHILDIS and a sloop were lost. Eight bodies were subsequently washed ashore or recovered from the cliffs.
Two burials are recorded in the Dinas Burial register for 30th October - Unknown drowned in a shipwreck during a terrific gale Oct 25th 1859. Abode, both Cardiganish as supposed'.
Potters Electric News, 2 November 1859, Welsh Newspapers Online