 From the mid-16th century onwards, the Devon Stannaries were worth very little in income to the King and were sidelined as such following the Supremacy of Parliament Act 1512 (this does not apply to the Stannaries of Cornwall).The landscapes of Cornwall and West Devon were radically reshaped during the 18th and 19th centuries by deep-lode mining for copper and tin.The underground mines, engine houses, foundries, new towns, smallholdings, ports, harbours, and ancillary industries together reflect prolific innovation which, in the early 19th century, enabled the region to produce two-thirds of the world's supply of copper.