If you looked at their mustard yellow and vibrant blue pants and chest covered by polished steel breast plate, you would not think the Pontifical Swiss Guard were real soldiers tasked with protecting the Pope. In fact the Swiss Guard are members of the Swiss military, trained not only in ceremonial duties, but unarmed combat and small arms usage in the name of protecting Vatican City.
In today's Swiss Guard armory you have modern SIG pistols and rifles that can be pressed into service to fend off any threat that makes it past the numerous other layers of traditional law enforcement security around the Vatican. Small arms are part of the inventory of Swiss Guard weapons, including a little known pistol that once served the Austro-Hungarian and Ottoman Empires, as well as Nazi Germany.
The Dreyse M1907 is an odd looking medium sized semi-automatic pistol.Chambered in 7.65mm Browning (.32ACP) the direct-blowback pistol is more unusual design than necessarily in operation. The slide sits above the the barrel, with an offset long z-shape. To operate the pistol you insert a seven-round box magazine into the grip and grasp the front of the slide above the barrel. Pulling the slide to the rear exposes the lower rear of the offset z-shape. The slide rests inside two flanges above the pistol and recoils forward, stripping a fresh round.
When fired, the same series happens with direct impingement of the bullet case against the slide, ejecting to the right through a cut out in the frame flange.
Essentially a standard direct blowback pistol the Dreyse M1907 is definitely odd looking but effective pistol. It's usefulness to armies was exemplified by its adoption with militaries during World War I and II. The simple design and method of operaiton made it reliable for field uses, while some of the Dreyse's contemporaries were more fussy when exposed to mud and dirt.
Another distinction for the Dreyse M1907, in addition to the Swiss Guard use, it was the first semi-automatic pistol used by law enforcement in Europe