The Italians in World War 1 (1914-1918) inadvertently created what was essentially the world's first submachine gun through its "Villar Perosa Modello 1915". This weapon coupled two barrels in a side-by-side arrangement, each with individual feeds and firing mechanisms to produce what was, by design, a Light Machine Gun (LMG) system intended as a light support weapon for Italian Alpine troopers. While showcasing a healthy rate-of-fire (1,200 rds/min), it suffered in the role with limited engagement ranges, utilized a blowback system of operation, and fired the 9mm Glisenti pistol cartridge - all qualities later associated with submachine guns. At any rate it laid the groundwork for more successful forms that followed - including its direct offshoot, the OVP ("Officine Villar Perosa").
Once the true value of the Modello 1915 was appreciated, a new weapon was born from work undertaken in 1916. This entry largely retained the original model's internal makeup and to this was added a wooden stock for shoulder support, a double-trigger unit under the receiver for select fire, and a longer barrel assembly for accuracy and robustness. A cylindrical metal cover acted as the weapon's receiver. The dual triggers offered fire selection between two modes - semi-automatic from the rear trigger and full-automatic from the forward trigger. Magazines held 25 rounds of 9mm Glisenti pistol cartridges and were inserted into the top of the receiver, ahead of the action and center mass of the weapon which proved awkward. The cocking handle was not a handle at all - instead it became a knurled sleeve set around the receiver and ahead and above the trigger unit. This was brought back and then forward to chamber the weapon. The rear sight was fitted ahead of the magazine well which limited its usefulness.
Overall, the weapon weighed a manageable 8lb and featured a length of 35.5 inches. Performance specs included a rate-of-fire of 900 rounds-per-minute and a muzzle velocity of 990 feet per second. The magazine held 25 ready-to-fire rounds.
The OVP was available in some number during 1918, the war's final year, but did not see formal issuance until the early 1920s. Like other Great War weapons, it had an extended service life and saw action into the early campaigns of World War 2 (1939-1945). The Italians fielded the type duirng its "Abyssinian War" against Ethiopia (the "Second Italo-Ehtiopian War" of 1935-1936) and the weapon continued to pop up during the North African campaign. By this point, the series was more or less supplanted by better-performing submachine guns offered by Beretta and the OVP was encountered much less after 1941.