The Italian military went into WWI having already adopted a semiautomatic sidearm – the Model 1910 Glisenti (and its somewhat simplified Brixia cousin). However, the 1910 Glisenti was a very complex design, and much too expensive to be practical for the needs of the global cataclysm that was the Great War. In response to a need for something cheaper, Tulio Marengoni of the Beretta company designed the Model 1915, a simple blowback handgun chambered for the 9mm Glisenti cartridge.
Only 15,300 of the Model 1915 pistol were made, because even they proved to be a bit more than the military really needed. One of their most interesting mechanical features is a pair of manual safeties – one on the back of the frame to lock the hammer and one on the left side to block the trigger. This proved a bit redundant, and the gun overall was rather large and heavy. In 1917 a scaled-down version in .32 ACP (7.65mm) was introduced which would be produced in much larger numbers. The 1915/17 would also omit the rather unnecessary hammer safety.
It is important to note that while the 9mm Glisenti cartridge is dimensionally interchangeable with 9×19 Parabellum, pistols designed for the Glisenti cartridge should *never* be used with standard 9×19 ammunition, as it is nearly 50% more powerful than the Glisenti specs, and doing so will quickly cause damage (and potentially catastrophic failure).