Originally, a type of projectile invented by the British artillery officer Henry Shrapnel (1761–1842), containing small spherical bullets and an explosive charge to scatter the shot and fragments of the shell casing.
A time fuse set off the explosive charge late in the shell's flight, when it was near opposing troops. The resulting hail of high-velocity debris was often lethal; it caused most of the artillery-inflicted wounds in World War I. In World War II a high-explosive bursting charge that fragmented the shell's iron casing made shrapnel balls unnecessary; the term shrapnel came to be used for the shell-casing fragments.