`Eccluis guiniau? (possibly meaning `white church?) is mentioned in an entry in the Llandaff Charters, from around 1025. Its location is unknown, but it may have been located at a field depicted as Castell Gwynne on the tithe map of 1840. The field is adjacent to Trefloyne Manor (NPRN 30327) late medieval gentry house (NPRN 30327), which is thought to occupy the site of a pre-Conquest high status settlement or llys known as ` Luin Teiliau?. The site is 400m west of Longbury Bank early medieval secular enclosure and some 1km west-northwest of SS Nicholas and Teilo's Church, Penally (NPRN 46847). The site is also noted to be intervisisble with the church towers at Tenby and Gumfreston.

Sources include:
Cambria Archaeology, 2003, Early Medieval Ecclesiastical Sites Project, Pembrokeshire gazetteer

N Vousden, 23 October 2018