The show tells the story of Dic Penderyn a Welsh labourer and coal miner who lived in Merthyr Tydfil who was involved with the Merthyr Rising of 3 June 1831. In the course of the riot he was arrested alongside Lewis Lewis, one of the primary figures in the uprising, and charged with stabbing a soldier with a bayonet. The people of Merthyr Tydfil doubted his guilt, and signed a petition for his release. However, he was found guilty and hanged on 13 August. After his death he was treated as a martyr in Merthyr and across Britain.