a market-town, parliamentary and municipal borough of Wales, in the county and 8 miles S.E. of Denbigh, 195 N.W. by W. of London. It stands on the sides and top of a hill on the left bank of the Clwyd. The ancient castle, which was founded by Edward I., was taken after a siege of two months by the parliamentary forces in 1646, and afterwards dismantled. Recently a castellated mansion-house has been erected on the site. In the market-place of the town stands the town-hall, a substantial building of the seventeenth century. Ruthin has also a handsome court-house, a grammar and other schools, and a jail. The church is ancient, and has a much-admired oak roof. The other places of worship belong to Baptists, Independents, and Methodists. The inhabitants are chiefly employed in farming. Markets are held twice a week, and there are several annual fairs. The borough is governed by a mayor, three other aldermen, and twelve councillors; and it unites with Denbigh, Holt, and Wrexham in returning a member to Parliament. Pop. (1851), 3373.