Sub-machine guns
As World War I bogged down in trench warfare, tacticians found that independent raiding parties, rather than massed attacks, were most suited for opening an assault. Long rifles with bayonets were quite unsuited for the task and so development began by all sides on a rapid-fire automatic weapon ideal for close-quarters fighting.
The German Hugo Schmeisser (whose name is often mistakenly attributed to the MP40) was the first to develop the MP18/I, a fully automatic personal weapon with the firepower of a machine gun. Narrowly beating the Italians to the scene, the first widely used, general-issue sub-machine gun was born.
The sub-machine-gun principle is simple: pistol-sized bullets could be fired rapidly using the most rudimentary of weapons, making even the most inexperienced user a formidable opponent. The advent of World War II, with its close-quarters and street fighting, saw the sub-machine gun widely used by all nations.
