The use of Tunnels in warfare goes back over 3,000 years when they were originally used to undermine the foundations of defenders walls. As the Western front developed into a continuous line of trenches it was not surprising that tunnels were once again used in what was effectively siege warfare. The method was to dig tunnels towards the enemy, digging chambers under their front line, filling then with explosives, then detonating them. The first use of military mining against British and Commonwealth troops occurred on 21st December 1914 when the Germans exploded ten small but deadly mines beneath the primitive trenches of the Indian Sirhind Brigade at Givenchy-lès-la Bassée. Following further mining action by the Germans, the first tunnelling companies of the Royal Engineers were formed in early 1915 and were at work in Flanders by March. Underground warfare began with each side trying not only to destroy defences on the surface, but each others tunnels and tunnellers. By mid 1916, there were around 25,000 tunnellers .
