an urban district in the western parliamentary division of Monmouthshire, England, on the Sirhowy river, 24 m. north of Cardiff, on a joint line of the London & North Western and the Rhymney railways. Pop. (1901), 18,497. It stands at an elevation of about loon ft., and owes its existence to the establishment in the beginning of the 19th century of the works of the Tredegar Iron and Coal Company, which employ most of the large industrial population. The place gave the title of Baron Tredegar (c. 1859) to Sir Charles Morgan Robinson Morgan, Bart. (1792-1875), whose grandfather, Sir Charles Gould, Bart., married the heiress of John Morgan of Tredegar and changed his name to Morgan. He was M.P. for Brecknock in 1835-1847. He married a granddaughter of the 1st Lord Rodney. His son Godfrey (b. 1830), who succeeded to the barony, was created Viscount Tredegar in 1905; he had served in the Crimea and taken part in the famous Balaclava charge.