While the Italians developed and issued the first submachine gun in World War 1, it was hardly the quintessential submachine gun form as we recognize it today for it featured a pair of spade-type grip handles, a support bipod and twin barrels fed by independent 25-round curved magazines inserted into the top of the frame. The weapon was first issued to Italian alpine troopers and used as a light machine gun support weapon - despite having many of the qualities (pistol cartridge, compact form, automatic action) of what is widely accepted today as a submachine gun. This weapon became popularly recognized as the "Villar Perosa" for its place of origin though also became known under the more formal FIAT-Revelli Modello 1915 for its manufacture brand (FIAT), designer (Revelli) and year of issuance (1915). The Villar Perosa appeared some two years before the heralded German Bergmann MP18 submachine gun, which brought about the classic submachine gun form, making the Italians the first to utilize a submachine gun-type weapon - though it would be some years before they appreciated the weapon they had and rewrote doctrine to accommodate their new gun.It only when the competing firm of Beretta took the original twin-barreled Villar Perosa and halved it to create a single-barreled form, added its own trigger group and a solid, single-piece wooden body, that the weapon finally took on a more definitive look and (ultimately) battlefield role. The Beretta Model 1918 was the resulting product and, once it was issued and used in a more traditional submachine gun assault role, original Villar Perosa guns were themselves reimagined into the single-barreled OVP. Original dual-barrel forms continued in service to the end of the war - though Italian doctrine concerning the type was rightfully revaluated and their use as light support weapons dwindled.Like many other weapons of modern warfare, the submachine was born in the trenches of World War 1 where thought was given to clearing out entrenched enemies. This required a portable weapon system that was controllable and offered a high rate of fire against infantry usually armed with long, bayonet-wielding service rifles - usually of the bolt-action type. While semi-automatic handguns offered only a partial solution (slow rate-of-fire, extremely limited ranges) they proved largely ineffective for the role. Similarly, machine guns of the period were large, cumbersome instruments requiring water-cooling canisters and ammunition to be toted from place to place. As such, this too proved an unlikely solution for trench-clearing sorties. This requirement gave rise to an in-between weapon in which a pistol cartridge allowed for controllable, portable fire and an automatic action allowed for the needed high volume assault. For the Italians, the Villar Perosa offered all these qualities, centered around the 9x19mm Glisenti pistol cartridge. The Glisenti cartridge was a version of the German 9x19mm Parabellum round though of much greater power which require use of much stronger recoil springs.The Beretta approach merely took the Villar Perosa design and modified it for role. Besides the added wooden frame and underslung trigger group, all other design functions remained faithful to the original Villar Perosa design. Beretta also added a folding bayonet system under the muzzle for extreme close quarters combat. Magazines were still inserted through the top of the frame with spent shell casings ejecting through the bottom. The trigger unit was well-formed and within easy reach of the grip handle which, itself, was integrated into the stock. In essence, the Villar Perosa was given a service rifle-style body for easier management. Large stocks of Villar Perosa guns were modified in this fashion, diminishing the numbers of the original guns considerably.In time, there proved two distinct versions of the Model 1918 - one with a single trigger and another, the "due grilletti", featuring two triggers to accomplish a semi-automatic and full-automatic fire action (original guns were semi-automatic only). The single trigger versions were, therefore, more akin to carbines than true submachine guns.Specifications for the new gun included a length of 33.5 inches, a barrel length of 12 inches and a weight of 3.25 kilograms. The weapon was fed via a 25-round detachable box magazine and offered a 900 round per minute rate of fire (considerably lower than the 1,200rpm of the original Villar Perosa). Muzzle velocity was rated at 1,250 feet per second (the Villar Perosa at 1,200fps).Despite their 1918 lineage, the Model 1918 was still in use by the time of World War 2 where stocks remained in number and, rightfully, pressed into service with Italian forces requiring use of the type. Operation beyond Italy also fell to Argentina and Albania.The Model 1918 was revisited and revised to a more modern form in 1930, producing the Beretta Model 18/30 offshoot. Primary differences included a bottom-feeding magazine system and adoption of the more popular and readily available German 9x19mm Parabellum pistol cartridge.