Langenhan, located in Zella St. Basil, Germany, was founded around 1842 by a family of gunsmiths that dated back to the 18th Century and made bicycles and firearms-- a common set of products at the time. For example, Fabrique Nationale--FN--used to be a big name in the bicycle game. When it came to boomsticks, Langenhan GmbH specialized in single-shot scheibenpistole (target pistols) but also branched out into hunting rifles, air guns (which is a whole 'nother story), umbrella guns, and even landed a military contract in the 1870s for S&W 1 1/2 revolver clones for the Royal Saxon Army.
Speaking of military contracts, when the Great War snuffed out the lamps across Europe in 1914, the rapidly expanding German military was desperate for weapons, to include sidearms for officers. Langenhan submitted a proposed "Heeres-Modell" or Army model, which was basically a scaled-up and modified Browning/FN 1900, that was adopted as an "Ersatz Pistolen," or substitute handgun. Chambered in 7.65 Browning-- which is .32 ACP on this side of the bratwurst-- the pistol was the same caliber as the Becker Beholla/Mintz Menta, Dreyse M1907, and Mauser M1914, other German-made autoloaders adopted as "Aushilfswaffe" or a backup weapon when the standard Luger was not available.
The Langenhan army model was an 8+1 .32 ACP blowback-action with a heel-mounted magazine release and a roughly 4-inch barrel with four-groove rifling. Also note the frame-mounted safety with "S" and "F", right side. It has a fixed blade front and rear V-notch sights. The barrel is on the bottom of the slide and the recoil spring on the top, as with the FN 1900.
The example above is marked "F. L. Selbstlader" which means "self-loading" and "D.R.G.M. 625263," the latter a sort of German "patent pending" (Deutsches Reiches Gebrauchs Musterschutz) number. There are also nitro proof marks and a stylized "F L" on the period natural rubber grips, as common with early guns in the series. Later models are usually seen with lined or slab-sided wooden grip panels as well as a second DRGM number.
Where it departed from Mr. Browning's design, the FL-Selbstlader used a breech block that was held in place by a combination stirrup lock/rear sight whose rear-facing screw can loosen and fall away over time as screws tend to do. This can result in the lock yoke getting out of position and the slide ejecting itself from the pistol during firing-- so have that screw examined along with the entire gun by a qualified gunsmith familiar with the design should you plan to fire it. At this point, it is probably best just to leave these 100~ year old autoloaders as collectibles. Despite the wandering screw issue, which arguably makes the gun super easy to disassemble, the gun is well-made and hails from a time when lots of hand fitting and machining were common in gun craft.
Speaking of which, as a byproduct of the German Army's back-to-back going out of business sales in 1918 and 1945, FL-Selbstladers are often seen in the collection of military museums across Europe, and the Americas, scattered across the globe after the World Wars. As a replacement standard, it never had the legs of other Teutonic martial pistols such as the Luger, Walther P-38/PP, and Mauser 1914/30, but has nonetheless proved increasingly collectible.
Never sold commercially, estimates range between 55,000 and 86,000 of these guns were made during the war, all for the German military with some supplied to their allies, the Bulgarians and Austrians. Once the war was over, there is some evidence that the former Army pistol was frequently reissued to German police units as many in circulation today have Weimar-era Polizei markings, and when the next war came was pressed into service with the military once again, as many came home in GI duffle bags.
As for Langenhan, after WWI, the company shrunk the Selbstlader down to a "Vest Pocket" sized .25 ACP version, dubbed the Model II and later Model III, which remained in production throughout the 1930s. During WWII, they once again returned to military production, making machine guns, and, once the Soviets came to town in 1945, boarded up and closed shop.
Still, the Selbstlader is sufficiently interesting enough to have earned a space in the collection of any discerning collector of firearms that are eccentric, or a bit out of the norm. After all, when have you seen two of them at the same time?