The tin mining industry on Dartmoor, Devon, England, is thought to have originated in pre-Roman times,[1] and continued right through to the 20th century, when the last commercially worked mine (Golden Dagger Mine) closed in November 1930 (though it saw work during the Second World War), and "composite mines" such as those producing tin as a by- product, such as Hemerdon Mine in Plympton continue to operate today. From the 12th century onwards tin mining was regulated by a stannary parliament which had its own laws.
Tin is smelted from cassiterite, a mineral found in hydrothermal veins in granite, and the uplands of Dartmoor were a particularly productive area. The techniques used for the extraction of tin from Dartmoor followed a progression from streaming through open cast mining to underground mining. Today, there are extensive archaeological remains of these three phases of the industry, as well as of the several stages of processing that were necessary to convert the ore to tin metal.