Siege became established as a perennial mode of human conflict ever since the first urbanised populations constructed walls to protect themselves from attack. In the annals of siege warfare, few commanded more fear and respect than the miner, who with his pick, shovel and crowbar was a serious threat to the strongest foundations. This book traces the development of undermining techniques from the earliest evidence of ancient and medieval siege warfare. The advent of gunpowder revolutionised the mine in the sixteenth century and sustained mining as an integral part of siege warfare in the eighteenth century.