According to Archdeacon Thomas, the parish of Llanrhaeadr yn Mochnant at one time included the Denbighshire parishes of Llanarmon Mynydd Mawr, Llangadwaladr, Llangedwyn and part of the Montgomeryshire parish of Llanwddyn.
Before the administrative re-organisation of 1974, the parish of Llanrhaeadr ym Mochnant consisted of the Denbighshire townships of Banhadla Ucha, Banhadla Isa, Gartheryr, Henfachau, Trebrys Fawr, Trebrys Fach, Trefeiliw, Tre'r-Llan and Tre-Wern; and the Montgomeryshire townships of Abermarchnant, Brithdir, Castellmoch, Cefn Coch, Glanhafon Fach, Glanhafon Fawr and Nantfyllon.
St. Mary's Church at Rhos y Brithdir, within the parish of Llanrhaeadr ym Mochnant, was opened on Monday, 18 July 1892 by the Bishop of St. Asaph.
Until the boundary revisions of 1974, it was in Montgomeryshire, whereas the parish church, of St. Dogfan, was in Denbighshire. Perhaps because of this, some family history databases and websites have assumed, quite incorrectly, that there are two parishes named Llanrhaeadr ym Mochnant. There are not!
• • •
For family history information about the church and parish, visit the GenUKI Llanrhaeadr ym Mochnant page.