The 7.58 cm Minenwerfer a.A. (alter Art or old model) (7.58 cm leMW) was a German

Germany

Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

 First World War mortar

Mortar (weapon)

A mortar is an indirect fire weapon that fires explosive projectiles known as bombs at low velocities, short ranges, and high-arcing ballistic trajectories. It is typically muzzle-loading and has a barrel length less than 15 times its caliber....

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The Russo-Japanese War

Russo-Japanese War

The Russo-Japanese War was "the first great war of the 20th century." It grew out of rival imperial ambitions of the Russian Empire and Japanese Empire over Manchuria and Korea...

 of 1905 had shown the value of mortars against modern fieldworks and fortifications and the Germans were in the process of fielding a whole series of mortars before the beginning of World War I. Their term for them was Minenwerfer, literally mine-thrower, and they were initially assigned to engineer units in their siege warfare role.