"A borough, a market and assize town, a parish, and the head of a poor-law union, in the hundred of Ruthin, county of Denbigh; 8 miles (SE by S) from Denbigh, and 210 miles (NW by W) from London. ..... This parish and that of Llanrhud, which were originally one, are bounded on the south by the parish of Llanfair, east by the same and that of Llanarmon yn Ial, west by Llanfwrog, and north by Llanbedr. ..... The surface is beautifully diversified, the eastern part of Llanrhud embracing a portion of the Clwydian hills, and the western part of Ruthin the meanderings of the river Clwyd, with the fertile and luxuriant meadows on its banks. ..... The agricultural produce is equally rich and abundant, yielding fine crops of wheat, barley, oats, potatoes, and turnips, together with grass and hay." [A Topographical Dictionary of Wales, 1833 & 1849, Samuel Lewis]
The ancient parish of Ruthin contained the two townships of Cae'rfallen and Tre'rcastell.