BBC Look at 'Black Miners'
Black miners played an integral role in the story of the Welsh coal industry, but it's a story that has rarely been told.
Historian Norma Gregory, who has been exploring the story of black miners across the UK, says she was initially told there had been none working in Welsh collieries.
But through a "very hard, long search", Ms Gregory believes about 200 black miners worked in the country from the 1800s onwards.
Former Wales international footballer Nathan Blake features in Wales' Black Miners, a documentary in which he searches for these forgotten men