This absorbing illustrated study reveals the evolving tactics and techniques used by all sides in the underground war during 1914–18. Covering the Western Front but also the Gallipoli and Italian theatres, this study explores three aspects of World War I below ground: military mining, attack tunnels and dugouts. In 1914–17, the underground war was a product of static trench warfare, essential to survive it and part of both sides’ attempts to overcome it. In 1917–18 it was rendered largely obsolete by the development of the all-arms battle as mobility was restored to the battlefield. In the stagnant, troglodyte existence of trench warfare, military mining was a hidden world of heroism and terror in which hours of suspenseful listening were spent monitoring the steady picking of unseen opponents, edging quietly towards the enemy, and judging when to fire a charge. Break-ins to enemy mine galleries resulted in hand-to-hand fighting in the darkness. The ingenuity, claustrophobia and