The mortar derives its name from the mortar and pestle that is still in use today in any laboratory in the world. The original idea was to lob a projectile over the walls of a castle and cause havoc inside. As with grenades, once warfare became mobile, the mortar seemed to fall into disuse. The real beginnings of modern mortars commences when the siege warfare of WWI demanded the return of the mortar to get at troops protected by elaborate earthworks. A Mr. Wilfred Stokes came to the rescue and developed the forerunner of all modern mortars. The 3 inch trench howitzer as it was called then.