The eighteenth and nineteenth centuries saw remarkable changes to the South Wales landscape, population and economy. This beautiful landscape of rugged valleys, fast flowing rivers and semi-uplands was one of the first places to be lit by the fires of the Industrial Revolution.
Ironworks, collieries, ironstone mines, coke works, tin plate works, quarries and copper works were opening across south Wales with thriving associated industries. The population of these industrial areas in south Wales witnessed unprecedented population booms as unparalleled numbers of workers migrated into the industrial areas to fill the jobs readily available at the expanding works.
Ribbons of stone built terraced houses were built rapidly along the valley sides to accommodate the enormous work force. Living conditions became crowded and, as the increasing population density put strain on the sanitation and health of the inhabitants, the death rates rose. Together with unsafe working practices in the burgeoning industries the mortality rates in the industrial towns was higher than at any other peace time era. The economy of these areas rose in general terms although the pay to the labour force was low. Huge levels of wealth were shared by only a few. The Ironmasters and colliery owners were in receipt of significant wealth from the huge demand that the world was placing on their products. The South Wales Coalfield, stretching from Kidwelly in the west to Pontypool in the east, housed more than forty ironworks by the middle of the nineteenth century.
The ironworks of Merthyr Tydfil have often been described as the ´Engine of Empire´, the technological leaders of their day, and more than any other area in Wales led the way in the production of iron and extraction of coal that the Industrial Revolution so heavily relied upon. By the middle of the nineteenth century there were five large ironworks in Merthyr Tydfil owned by ironmasters who were to become significant names in Merthyr's history. Perhaps the most famous and celebrated of these Ironmasters were the Crawshay family.