This book, first published in 1978, examines the independent political action by the thousands of working people in the town of Merthyr Tydfil, Wales. After a mass rally on the hills above the town, thousands of workers under a reg flag broke into insurrection – a detachment of Argyll and Sutherland Highlanders marched into the town to restore order. The rebels repulsed the soldiers and held the town, with at least two dozen workers killed. Within weeks of the Rising, trade unions began to appear in South Wales, and this book argues that these events were central to the emergence of a Welsh working class.