[4] What is now Merthyr Tydfil County Borough was situated close to reserves of iron ore, coal, limestone and water, making it an ideal site for ironworks.

They often shared routes to enable access to coal mines and ironworks through rugged country, which presented great engineering challenges.

The tramway passed through what is arguably the oldest railway tunnel in the world, part of which can still be seen alongside Pentrebach Road at the lower end of the town.

At its peak, the Dowlais Iron Company operated 18 blast furnaces and employed 7,300 people, and by 1857 had constructed the world's most powerful rolling mill.

Thomas Carlyle visited Merthyr town in 1850, writing that it was filled with such "unguided, hard-worked, fierce, and miserable-looking sons of Adam I never saw before.

It is like a vision of Hell, and will never leave me, that of these poor creatures broiling, all in sweat and dirt, amid their furnaces, pits, and rolling mills.

"[7] The Merthyr Rising of 1831 were precipitated by a combination of the ruthless collection of debts, frequent wage reductions when the value of iron periodically fell, and the imposition of truck shops.

Some 7,000 to 10,000 workers marched and, for four days, magistrates and ironmasters were under siege in the Castle Hotel, and the protesters effectively controlled Merthyr.

One of them, Richard Lewis, popularly known as Dic Penderyn, was hanged for the crime of stabbing a soldier named Donald Black in the leg.

A more serious political history of these events, The Merthyr Rising was written by the Merthyr-born Marxist writer Professor Gwyn A. Williams in 1978.

By 1932, more than 80% of men in Dowlais were unemployed; Merthyr experienced an out-migration of 27,000 people in the 1920s and 1930s, and a Royal Commission recommended that the town's county borough status should be abolished.

In the post-war years the local economy became increasingly reliant on light manufacturing, often providing employment for women rather than men.

In 1987, the iron foundry, all that remained of the former Dowlais ironworks, finally closed, marking the end of 228 years continuous production on one site.

In October 1948 the American-owned Hoover Company opened a large washing machine factory and depot in the village of Pentrebach, a few miles south of the town.

In 1992, while testing a new angina treatment in Merthyr Tydfil, researchers discovered that the new drug had erection-stimulating side effects for some of the healthy volunteers in the trial study.

[9] In 2006 inventor Howard Stapleton, based in Merthyr Tydfil, developed the technology that has given rise to the recent mosquitotone or Teen Buzz phenomenon.

Despite recent improvements, some parts of the County Borough remain economically disadvantaged, and there is a significant proportion of the community who are long-term unemployed.

The Bedlinog community covers the area that was transferred to the borough of Merthyr Tydfil in 1974 from Gelligaer Urban District under the Local Government Act 1972.

As well as the village of Merthyr Tydfil itself, the parish covered much of the upper Taff Valley, including settlements stretching from Dowlais in the north to Aberfan and Treharris in the south.

As the area rapidly developed during the industrial revolution, it was decided that a more formal type of local government was required, particularly to oversee sanitation and public health in the parish.

[22][23] In 1935, a Royal Commission argued that Merthyr Tydfil County Borough, then heavily burdened by the cost of maintaining many unemployed people, should be abolished and merged with Glamorgan.

[27] Merthyr Tydfil County Borough is home to several established choirs who perform frequently in the local area and abroad.

Local poets and writers hold poetry evenings in the town, and music festivals are organised at Cyfarthfa Castle and Park.

Merthyr Tydfil Housing Association, working in partnership with Canolfan Soar, has been successful in raising funding to turn the Pontmorlais area into a cultural quarter.

The county borough has produced several bands which have achieved national success, including The Blackout from Heolgerrig and Midasuno from Troedyrhiw.

The Fforest Fawr Geopark, designated in 2005 in respect of the area's outstanding geological and cultural heritage, also falls within the northern border of Merthyr Tydfil County Borough.

as part of the Interreg Collabor8 project, and will be working in partnership with the Brecon Beacons National Park Authority to promote the region across Europe.

Road improvements mean the county borough is increasingly a commuter location and has shown some of the highest house price growth in the UK.

Hoover (now part of the Candy Group) has its registered office in the town and remained a major employer until it transferred production abroad in March 2009, resulting in the loss of 337 jobs after the closure of its factory.

[38] Merthyr Tydfil Golf Club is situated on the southeastern slopes of Cefn Cil Sanws, a rough gritstone and limestone hill in the north-west of the County Borough.