MERTHYR TYDFIL, or MERTHYR TYDVIL, a municipal, county and parliamentary borough, and market-town of Glamorganshire, south Wales, situated in a bleak and hilly region on the river Taff, on the Glamorganshire Canal, and the Brecon and Merthyr, Great Western, North Western, Taff Vale and Rhymney railways, 25 m. N.N.W. of Cardiff, 30 E.N.E. of Swansea, and 176 from London. Pop. (1901), 69,228. The town is said to have derived its name from the martyrdom of St Tydfil, daughter of Brychan, who was put to death by Saxons in the sth century. It is for the most part irregularly built and was formerly subject to severe epidemics due todefective sanitation ; but it now possesses a supply of the purest water from the lesser Taff on the southern slope of the Breconshire Beacons. The. town owes its early industrial prosperity to the abundant ironstone and coal of the district, and it thus, became at an early date the chief seat of the iron industry in Wales. Four great ironworks were established here between 1759 and 1782. With the earliest, that of Dowlais, the Guest family were associated, first as partners and later as sole owners from 1782 to 1901 when the works were disposed to the company of Guest, Keen and Nettlefold. In 1765, Cyfarthfa was started by Anthony Bacon, and when firmly established, sold in 1794 to Richard Crawshay by whose descendants the works were carried on till the owners formed themselves in 1890 into a limited company (Crawshay Brothers Cyfarthfa Limited), the controlling interest in which has since been acquired by the Dowlais Company. The Plymouth works, started soon after Cyfarthfa, by Wilkinson and Guest, passed later into the hands of Anthony Hill from whose descendants they were purchased in 1863. They were closed down in 1882, but the collieries belonging to them continue to be worked on a large scale, yielding over 2000 tons of coal a day. The fourth great ironworks were those of Pen-y-darran which were carried on from 1782 to 1859. It was at Dowlais (in 1856) that Bessemer steel was first rolled into rails, but the use of puddled iron was not wholly abandoned at the works till 1882. It has now eighteen blast furnaces, and extensive collieries are also worked by the company, and large branch works were opened on the sea-board at Cardiff in 1891. Cyfarthfa was converted into steel works in 1883. The iron ore used is mainly imported from Spain. Merthyr Vale is almost entirely dependent on coal-mining and has one of the largest collieries in south Wales (Nixon's Navigation). The population of this district more than quintupled between 1881 and 1901.
From 1850 the government of the town was vested in a local board of health which in 1894 became an urban district council; by charter granted on the 5th of June 1905, it was vested in a corporation consisting of a mayor, 8 aJdermen and 24 councillors. It was made a county borough from the 1st of April 1908. It comprises about 17,759 acres, is divided into eight wards and besides the older town, it includes Penydarran (i m. N.E.), Dowlais (2 m. N.E.), Plymouth (i m. S.) and Merthyr Vale (5 m. S.). It has a separate commission of the peace, and in conjunction with Aberdare and Mountain Ash, has had a stipendiary magistrate since 1829. The parliamentary borough which was created and given one member in 1832 and a second in 1867, includes the parish of Aberdare and parts of the parishes of Llanwonno, Merthyr Tydfil and Vainor (Brecon).
There is an electric tramway (completed in 1901) from the town to Cefn and Dowlais. In 1901 about 50% of the population above three years of age spoke both Welsh and English, 7!% spoke Welsh only, and the remainder English only. The ancient parish of Merthyr Tydfil has been divided into five ecclesiastical parishes (Merthyr, Cyfarthfa, Dowlais, Pentrebacb, and Penydarran) and part of another parish (Treharris). These six parishes form the rural deanery of Merthyr in the archdeaconry and diocese of Llandaff, and in 1906 had nine churches and fifteen mission rooms. An inscribed stone (Artbeu) has been built into the east wall of the parish church; and two other inscribed stones removed from Abercar Farm in the greater Taff valley now lie in the parish churchyard. The old structure of the parish church has been entirely removed except the base of the tower. There is a Roman Catholic church in Penydarran Park and another at Dowlais. The Nonconformists, of which the chief denominations are the Baptists, Congregationalists and Methodists Wesleyan and Calvinistic had in 1906 82 chapels, 49 of which were used for Welsh services and 33 for English.
The public buildings include, besides the churches, a town hall and law courts (1898), drill hall (1866), library, market house, a county intermediate school, general hospital built in 1887 and enlarged in 1897, and an isolation fever hospital, a theatre (1894) and a fountain presented by Sir W. T. Lewis as a memorial to the pioneers of the town's industry. At Dowlais there are public baths (1900) and a free library which have been provided by the owners of the Dowlais Works, Oddfellows' hall (1878), and a fever hospital (1869). At Thomas Town there is a recreation ground of 16 acres, formed in 1902. In 1908 the corporation purchased Cyfarthfa Castle (formerly the residence of the Crawshay family) with a park of 62 acres including a lake of 6 acres.
The Roman road from Cardiff and Gelligaer to Brecon passec through Merthyr and the remains of a supposed fort were discoverec in Penydarran park in 1902. Three miles to the north of Merthyr on a limestone rock about 470 ft. above the lesser (eastern) Taf are the ruins of Morlais Castle, built about 1286 by Gilbert de Clare on the northern limits of his lordship of Glamorgan, its erection causing a serious feud between him and de Bohun, earl of Hereford, who claimed its site as part of the lordship of Brecknock.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)