On the morning of 1 July 1916, the first day of the Battle of the Somme during World War I, underground explosive charges planted by British tunnelling units were detonated beneath the German front lines. The joint explosion of these mines ranks among the largest artificial non-nuclear explosions. In addition to the mines, the British tunnelling units also prepared a series of shallow saps extending from the British positions into the no man's land. They allowed the infantry to attack the Germans from a comparatively short distance once the battle commenced.