The Romans carried out mining in the area, but Dylife mining operations came into their own over the period 1818-1891. To give you an idea of the scale of the operation, from 1845 over 36,000 tones of lead ore were extracted, along with substantial quantities of copper and zinc ore, plus some silver. At one stage the mines were owned by Cobden and Bright, the social reformers, and one might hope that living conditions were better than at mines elsewhere in Wales. Nevertheless, there were never more than 100 dwellings at Dylife to accommodate 1000-1500 workers, and TB and fever were well known. Dylife boasted possibly the largest water wheel ever erected in Wales, the 63ft diameter Red Wheel, and the wheel pit can still be seen. The top section of 600ft of pump rods that the wheel drove can also still be seen sticking up out of the Llechwedd Ddu shaft, like a gaunt memorial.
There are a number of Web sites dedicated to the history of Dylife, and the best I've found are:
http://www.abandonedcommunities.co.uk/page22.html. A useful write-up of the history of the area.
http://www.mike.munro.cwc.net/mining/dylife/dylife.htm Stupendous, surely unique, underground photos of the mines, plus a good old map.
http://www.mike.munro.cwc.net/mining/wms/meets/1999/fm_99-06.htm#Dylife Above ground photos by the same guy.
http://history.powys.org.uk/history/llani/dylife1.html and http://history.powys.org.uk/history/llani/dylife2.html include a photo of the community and the big wheel taken in 1852, a short history of the mines, plus photographs of the big wheel.
There's a gruesome story relating how in 1720 Siôn y Go(f), the local smith, murdered his wife and daughter (or former lover and her two children, depending upon your source), threw their bodies down a mine shaft and let it be known that they had left him. However, the bodies were discovered, he was found guilty of their murder, and executed. His body was hung in a gibbet on nearby Penygrocbren (Gallows or Gibbet Hill), and it is said that as the smith he had to make his own gibbet. The hanging irons were dug up in 1938, and today they and Siôn's skull are on exhibition at St. Fagans Folk Museum, near Cardiff. Activities at Penygrocbren go back further than this little episode though, it being the site of a Bronze Age burial mound. There's also evidence nearby of Roman occupation, with the outline of a Roman fortlet visible (reportedly built to protect Roman mining operations) and a Roman road.
The Miner's Ghost
Another tale tells of a Dylife miner who was killed in a mining accident and buried in the local graveyard. His clothes were buried separately, according to a local custom, near a place called called Ty Maggi. His ghost appeared on several occasions, waving a jacket at his friends and telling them to dig it up. When finally they did so, they found his life's savings in his pocket, which they shared between themselves, and the ghost only appeared once again, just to smile and wave goodbye!