The Parish Church is situated in the centre of the village. It is believed the village stood in the Middle Ages but evidence shows that the Church site, as a sacred spot, is much earlier probably pre 8th Century. The earliest Norman Church was probably built by Jordan de Cantington, benefactor of St Dogmaels Abbey who owned much of the land in the area. Few records remain regarding taxation except for Ecclessia de Clesserrow 1291 Tax £4 Egglosserowe 1535 Tax £3.13.4 During the Middle Ages the Rectory was in the possession of St Dogmaels Abbey. Opinions differ as to the derivation of the place name of Eglwyswrw. Some accept Eglwyswrw simply as Eglwys-erw, ie the Church acre. Some take the word Eglwys-hwrwg, ie the Church erected on a small hillock; others as meaning Eglwys-swrwd.ie Church erected on or by the ruins of an older building. Perhaps the most acceptable form is Eglwys-Eirow.ie the Church of St Eirow or Erw. An old chalice of the church bears the inscription POCULUM ECCLESIAE EIROW. 1574. Prior to the year 1881 there existed on the south side of the church a transept that is said to have been removed because it was too dilapidated to be restored. In Fentons ;Historical Tour Through Pembrokeshire he says . In the reign of Queen Elizabeth 1 there was a sort of chantry chapel in the church yard wherein on the South side was shown the tomb of the saint (St Erw?) in hewn stone. The parishioners never buried in the chapel from a superstitious belief the corpses there interned would in the night time be ejected as their Holy Saint would not have any bedfellow with him. Fragments of a piece of mullion and sill from the chantry may be seen in the wall of the present porch. However St Eirow or St Erw does not appear on the list of British Saints and yet in some manner the Church at Eglwyswrw has been dedicated to St Cristiolus. St Critiolus was the son of Hywel ab Emyr Llydaw and the brother of Saints Sulien and Rhhystud. The festival of St Cristiolus falls on the 3rd November, the same day as St Non, the mother of St David, the Patron Saint of Wales.