Peoples migrating north from
Europe had lived in the area for many thousands of years. The
archaeological record starts from about 1000 BC with the
Celts. From their language, the
Welsh language developed.
Hillforts were built during the
Iron Age and the tribe that inhabited them in the south of
Wales were called the
Silures, according to
Tacitus, the Roman historian of the
The Roman invasion
The Romans arrived in
Roman Wales by about 47–53 AD and established a network of
roads to link them. They had to fight hard to consolidate their conquests, and in 74 AD they built an
auxiliary fortress at
Penydarren, overlooking the
River Taff. It covered an area of about three
hectares, and formed part of the network of roads and fortifications; remains were found underneath the football ground where
Merthyr Tydfil FC play. A road ran north–south through the area, linking the southern coast with
Mid Wales and
Watling Street via
Brecon. Parts of this and other roads, including
Sarn Helen, can be traced and walked.
Silures resisted this invasion fiercely from their mountain strongholds, but the
Romans eventually prevailed. In time, relative peace was established and the Penydarren fortress was abandoned by about 120 AD. This had an unfortunate effect upon the local economy, which had come to rely upon supplying the fortress with beef and grain, and imported items such as oysters from the coast. Intermarriage with local women had occurred and many auxiliary veterans had settled locally on farms.
Decline of the Roman Empire,
Roman legions were withdrawn around 380 AD. By 402 AD, the army in
Britain comprised mostly Germanic troops and local recruits, and the cream of the army had been withdrawn across to the continent of Europe. Sometime during this period, Irish Dalriadan (Scots) and
Picts attacked and breached
Hadrian's Wall. During the 4th and 5th centuries the coasts of Cambria (Wales) had been subject to the raids of Irish pirates, in much the same way as the south and east coasts of Britain had been raided by
Saxon pirates from across the
North Sea. Around the middle of the 5th century, Irish settlements had been established around
Swansea and the
Gower Peninsula and in
Pembrokeshire and eventually petty kingdoms were establish as far inland as Brecon. By about 490 AD hordes of
Saxons invaded and settled in the east or "lowland" Britain and the locals were left to their own devices to fight off these new invaders.
The coming of Christianity
Latin language and some
Roman customs and culture became established before the withdrawal of the Roman army. The
Christian religion was introduced throughout much of Wales by the Romans, but locally it may have been introduced later by monks from
France, who made their way into the region following rivers and valleys.
Local tradition holds that a girl called
Tydfil, daughter of a local chieftain named
Brychan, was an early local convert to
Christianity, and was pursued and murdered by a band of marauding
Saxons while travelling to Hafod Tanglwys in
Aberfan, a local farm that is still occupied. The girl was considered a
martyr after her death in around 480. "Merthyr" translates to "Martyr" in
Merthyr History website.
The Normans arrive
For several hundred years the valley of the
River Taff was heavily wooded, with a few scattered farms on the mountain slopes.
Norman barons moved in after the
Norman Conquest of England, but by 1093 they occupied only the lowlands; the uplands remained in the hands of the local Welsh rulers. There were conflicts between the barons and the families descended from the Welsh princes, and control of the land passed to and fro in the
Welsh Marches. During this time
Morlais Castle was built two miles north of the town.
Early modern Merthyr
No permanent settlement was formed until well into the
Middle Ages. People continued to be self-sufficient, living by farming and later by trading. Merthyr was little more than a village. An
ironworks existed in the
parish in the
Elizabethan period, but it did not survive beyond the early 1640s at the latest. In 1754, it was recorded that the valley was almost entirely populated by
shepherds. Farm produce was traded at a number of markets and fairs, notably the Waun Fair above
The Industrial Revolution
Influence and growth of iron industry
Early 19th century industry in Merthyr Tydfil
Merthyr was close to reserves of
lumber and water, making it an ideal site for
ironworks. Small-scale iron working and coal mining had been carried out at some places in
South Wales since the Tudor period, but in the wake of the
Industrial revolution the demand for iron led to the rapid expansion of Merthyr's iron operations. By the peak of the revolution, the districts of Merthyr housed four of the greatest Ironworks in the world being those of Dowlais, Plymouth, Cyfarthfa and Penydarren.
 The companies were mainly owned by two dynasties, the
Crawshay families. The families supported the establishment of schools for their workers.
Starting in the late 1740s, land within the Merthyr district was gradually being leased for the smelting of iron to meet the growing demand, with the expansion of smaller furnaces dotted around South Wales.
 By 1759, with the management of John Guest, the
Dowlais Ironworks was founded. This would later become the Dowlais Iron Company and also the first major works in the area. Following the success at Dowlais, Guest took a lease from the Earl of Plymouth which he used to build the Plymouth Ironworks.
 However, this was less of a success until the arrival in 1763 of a "Cumberland ironmaster,
Anthony Bacon, who leased an area of eight miles by five for £100 a year on which he started the
Cyfarthfa Ironworks and also bought the Plymouth Works".
 After the death of Anthony Bacon in 1786, the ownership of the works was sold by Bacon's sons and divided between Richard Hill, their manager and
Richard Crawshay. Hill now owned the Plymouth Iron Works and Crawshay the works at Cyfarthfa. The fourth ironworks was
Penydarren, built by
Francis Homfray and his son
Samuel Homfray in 1784.
During the first few decades of the 19th century, the ironworks at
Cyfarthfa (and neighbouring Dowlais) continued to expand and at their height were the most productive ironworks in the world. 50,000 tons of rails left just one ironworks in 1844, for the railways across Russia to Siberia. With the growing industry in Merthyr, several railway companies established routes linking the works with ports and other parts of Britain. They included the Brecon and Merthyr Railway,
Vale of Neath Railway,
Taff Vale Railway and
Great Western Railway. They often shared routes to allow access to coal mines and ironworks through rugged country, which presented great engineering challenges. According to David Williams, in 1804, the world's first railway
steam locomotive, "The Iron Horse", developed by the Cornish engineer
Richard Trevithick, pulled 25 tons of iron with passengers on the new
Merthyr Tramroad from
 He also claims that this was the "first 'railway' and the work of George Stephenson was merely an improvement upon it".
 A replica of this is in the
National Waterfront Museum in Swansea. The tramway passed through what is arguably the oldest railway tunnel in the world, part of which can be seen alongside Pentrebach Road at the lower end of the town. The demand for iron was also fuelled by the
Royal Navy, which needed cannon for its ships, and later by the railways. In 1802,
Admiral Lord Nelson visited Merthyr to witness cannon being made.
Famously, upon visiting Merthyr's districts aforementioned in 1850,
Thomas Carlyle wrote that the town was filled with such "unguided, hard-worked, fierce, and miserable-looking sons of Adam I never saw before. Ah me! 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."
Living conditions in Merthyr’s slum China
China was the name given to the slum in the Pont-Storehouse region of Merthyr Tydfil. The inhabitants of China were seen as a separate class, away from the respectable areas of Merthyr, and were clearly recognisable by their lifestyle and appearance. In his article, In search of the Celestial Empire, historian Keith Strange compares China to areas of Liverpool, Nottingham and Derby, and states that this area was just as bad if not worse than these "little sodoms".
The worst of housing conditions were to be found in this area, and China was also home to what many regarded as a criminal class. The inhabitants became known as the Chinese and formed a society that became known as the "Empire".
In the 1840s a typical Merthyr family would be anything of up to four or five people; this was mainly due to more children surviving infancy, people living longer, immigration, and in particular large numbers of immigrants coming from Ireland fleeing the potato famine and unemployment that plagued their own country. In itself, the slum China saw at least 1,500 people congregated in its streets; stereotypically all of whom
were "unhappy and lawless". The slum's inhabitants were the poorest of society and had a bad reputation. Their living conditions were some of the most squalid in Britain. The slum was based around narrow streets, badly ventilated and full of crowded houses that led to festering diseases. China became known as "Little Hell"’ and was notorious for having no toilets but open sewers which caused diseases such as cholera and typhoid. Lice were common, especially amongst workers who worked and slept side by side in the cramped conditions of the slum. These conditions were a concern for the health visitors and housing inspectors who visited its dirty streets. Some of the most memorable and detested dwellings in the slum were the cellars, which were mere one or two roomed houses close together, and often with an outrageous number of inhabitants. In the 19th century, people lived in cellars only if could not afford anything better; or perhaps they preferred being within four cell walls as they had proper shelter and were fed daily.
Poor living conditions and poverty led to the evolution of crime in China. Perhaps the number of children who committed crimes might have been reduced if the standards of living had been higher. Some of these children were living with their families in these desperate conditions, but there were also numerous homeless, destitute children living on the streets. Many children were turned out of their home and left to fend for themselves at an early age, and many more ran away because of ill treatment.
Many youngsters who had experienced the living conditions in China's slum had grown up in a culture of poverty and often saw criminal offences, such as petty theft, as the only way to get regular meals. These meals were provided in the warmth of a prison cell, conditions many were unfamiliar with. Living conditions were so bad in China's slums that for many young offenders sent to prison, the prospect of regular meals and a roof over their head was an improvement on their normal living conditions.
The Merthyr Rising
Industrial Revolution, there was a dramatic decline in young men working in agriculture. Instead they were attracted by the higher wages available in industries such as iron. In 1829, the depression strongly affected Merthyr. Workers' rights did not exist; and sudden dismissal, wage reductions and short-term working had always been imposed by the ironmasters to maximise their profits. The sudden downturn in the market saw the ironmasters quickly dismiss surplus workers and cut the wages of those in work. The working classes were then immediately plunged into hardship, widening the gap in class hierarchy.
Merthyr Rising of 1831 was precipitated by a combination of the ruthless collection of debts, frequent wage reductions, and the imposition of
truck shops. Some workers were paid in specially minted coins or credit notes, known as "truck", which could be exchanged only at shops owned by their employers. Many of the workers objected to both the price and quality of the goods sold in these shops.
Throughout May 1831, the coal miners and others who worked for
William Crawshay took to the streets of Merthyr Tydfil, calling for reform, and protesting against the lowering of their wages and general unemployment.
Between 7,000 and 10,000 workers marched, and for four days magistrates and ironmasters were under siege in the Castle Hotel, with the protesters effectively controlling the whole town. Soldiers, called in from
Brecon, clashed with the rioters, and several on both sides were killed. Despite the hope that they could negotiate with the owners, the skilled workers lost control of the movement. Several of the supposed leaders of the riots were arrested. One of them, popularly known as
Dic Penderyn, was hanged for stabbing a soldier in the leg, becoming known as the first local working-class martyr. It was claimed in 1876 that it was not Lewis who stabbed Black, but another man, Ianto Parker, who fled to America following the incident in order to avoid prosecution.
 These claims have never been fully verified, although Lewis' innocence is widely accepted throughout Merthyr.
The Chartist movement of 1831 did not consider the reforms put forward by
The Reform Act of 1832 to be extensive enough.
The decline of coal and iron
The population of Merthyr reached 51,949 in 1861, but went into decline for several years thereafter. As the 19th century progressed, Merthyr's inland location became increasingly disadvantageous for iron production. Penydarren closed in 1859 and Plymouth in 1880; thereafter some ironworkers migrated to the United States or even
Ukraine, where Merthyr engineer
John Hughes established an ironworks in 1869, creating the new city of
Donetsk in the process.
In the 1870s the advent of
coal mining to the south of the town gave renewed impetus to the local economy and population growth. New mining communities developed at
Bedlinog, and the population of Merthyr rose to a peak of 80,990 in 1911. The growth of the town led to its grant of
county borough status in 1908.
A prime example of the decline is the Cyfarthfa Ironworks.
Robert Crawshay ('Iron King') can be seen as one of the main reasons for the downfall of Cyfarthfa. The Crawshays refused to modernise by replacing iron production with steel production, using the newly discovered
Bessemer process. This led to the closure of the works in 1874, which caused economic hardship and unemployment in Merthyr.
After Robert's death in 1879 his son
William Thompson Crawshay took over the Cyfarthfa works. William finally modernised the works, introducing steel production. However it took until 1882 to get the works back up and running. It never fully caught up with the times and with other steel making areas. The ironworks closed once again in 1910. The works briefly made a comeback during the
First World War but finally closed for good in 1919.
The local steel and coal industries began to decline after World War I. By 1932, more than 80% of men in
Dowlais were unemployed; 27,000 people emigrated from Merthyr in the 1920s and 1930s, and a Royal Commission recommended that the town's county borough status should be abolished. The fortunes of Merthyr revived temporarily during World War II, as war industry was established in the area.
Post-Second World War
Immediately following the
Second World War several large companies set up in Merthyr. 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. The factory was purpose-built to manufacture the Hoover Electric Washing Machine, and at one point Hoover was the largest employer in the borough. Later the
Sinclair C5 was built in the same factory.
Hoover and other companies targeted Merthyr due to its worldwide reputation amongst industry and trading
, and its declining coal and iron industries gave space for new businesses to start up there and grow. It was the Hoover company's aim to expand worldwide, and having already established bases in England and Scotland, Merthyr Tydfil seemed like the next appropriate step. There were ever increasing numbers of unemployed workers in the area, and since the Second World War this included women too. "Initially 350 people were employed, by the mid 1970s that number had risen to near 5,000; making Hoover the largest employer in the borough", and therefore strongly filling in for the declining coal and iron industries.
The growing employment of women in Merthyr after the Second World War is extremely significant and can be seen as a result of the introduction of more light manufacturing and consumer-based business – a stark contrast to the heavy industry in the coal and ironworks which had an almost entirely male workforce.
Several other companies built factories, including the aviation components company Teddington Aircraft Controls, which opened in 1946 and closed in the early 1970s. The Merthyr Tydfil Institute for the Blind, founded in 1923, is the oldest active manufacturer in the town.
Cyfarthfa, the former home of the ironmaster
William Crawshay II, an opulent mock-castle, is now a museum. It houses a number of paintings of the town, a large collection of artefacts from the town's Industrial Revolution period, and a notable collection of
Egyptian tomb artefacts, including several
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. This discovery formed the basis for
In 2006 inventor Howard Stapleton, based in Merthyr Tydfil, developed the technology that gave rise to the recent mosquitotone or
Teen Buzz phenomenon.