Battle of the Somme
Mines are a way to blow up the enemy and really shock them. Anti-infantry land mines have been in use since the invention of gunpowder and were used in the defense of breaches of fortresses in the 18th and 19th century (the British assault on the breach at Badajoz suffered many casualties from mines).  However these were activated remotely by a defender lighting a very fast burning fuse at the appropriate moment.  The British used 11 mines on the first morning of the Battle of Somme to startle and damage the German front line.  The holes left by the mines were used by the Germans for machine guns afterwards. The soldiers that set the land mines were called sappers.