"The consolidated chapelry of Rhesycae was constituted by an Order in Council, June 27th, 1848, out of the township of Hendrefigillt, in Halkin, the township of Trellyniau, and part of that of Llysdianhunedd, in Cilcain, and that portion of the township of Trellan Ucha, in Ysceifiog, which lies to the south of the ridge of Penucha'r Plwyf, and abuts on Rhesycae."
[From The History of the Diocese of St. Asaph , Ven. D.R. Thomas, 1908-1911]
The new parish of Rhesycae was created on 27 June 1848, from parts of the parishes of Halkyn, Cilcain and Ysceifiog: