"A parish in the Union of St. Asaph, higher division of the hundred of Isaled, county of Denbigh; 8 miles (W) from Denbigh, containing 1383 inhabitants. ..... The village is pleasantly situated at the head of the river Aled, which rises in Llyn Aled at no great distance, and in its course through the vale forms some interesting and picturesque cascades. The parish comprises a very considerable tract of arable and pasture land, of which by far the greater portion is enclosed; the soil, though various, is tolerably fertile. The surrounding scenery is almost totally devoid of natural beauty, and the country adjacent presents little more than an uninviting prospect of dreary wastes and mountains beyond." [A Topographical Dictionary of Wales, 1833 & 1849, Samuel Lewis]
The ancient parish of Llansannan comprised the townships of Treflach, Mostyn and Hendreunig, Llansannan, Rhydeidon, Beidiog, Penaled (or Pennant Aled), Llysaled, Archwedlog, Chwibren, Hescin, Deunant, Arllwyd, and Grugor; with a total area of 18,473 acres.
However, by an Order in Council on July 21st, 1855, the new parish of Bylchau was created; and the township of Grugor, with portions of Archwedlog and Deunant (a total area of 2873 acres) were transferred from Llansannan to Bylchau.