Without a doubt, the P-08 semi-automatic pistol is one of the most famous firearms of the 20th century. It's distinctive toggle lock and sleek lines make it very recognizable, as do the fact that it was a standard sidearm of the German armed forces for a period spanning nearly a half century, and produced in large quantities. It is well-known even to many people who know or care nothing about historic firearms.
The P-08 is a reasonably accurate pistol with a fixed bbl and comfortable grip to frame angle, however the tight manufacturing tolerances proved it to be unreliable in the battlefield conditions of the Great War.
Georg Luger, an employee of Loewe & Co., took the Borchardt pistol as a starting point for designing the first pistols resembling what would become the P-08. This included the development of a new cartridge, the 7.65 Parabellum (aka 7.65x23 and .30 Luger,) which is a 2mm shorter version of the Borchardt cartridge with a different powder charge. In addition to the new cartridge, he also designed a less complex mechanism. While the toggle-lock of the Borchardt was retained, the bizarre mainspring and correspondingly large housing it necessitated was replaced by a leaf spring in the grip, greatly improving the balance. The grip was given a more ergonomic angle and a grip safety was added to the rear of the frame by 1904.
After making these changes, Loewe vigourously sought military contracts for production of the pistol, and it was entered into the 1898 Swiss Army trials. Here it was received with success and was adopted as the Ordonnanz Pistole 1900 in 7.65mm, to be produced both at DWM and the Bern Arsenal. They are readily identifiable by, (amongst other things,) the Helvetic cross above the chamber.
A number of other countries evaluated the weapon, including the USA, for which Loewe & Co. manufactured a small number in .45ACP. The reliability let the pistol down and the sidearm accepted was that which became the model 1911. They were also sold commercially in this period, but were never a big seller due to the high price.
In an attempt to allay concerns about poor "stopping power" of the rd, Luger developed a second cartridge, the 9mm Parabellum (aka 9x19, 9mm NATO and 9mm Luger.) The cartridge case has the same base dimensions as the 7.65x23, but is shorter and not bottlenecked. A number of design changes to the pistol were made in the early 1900s, including replacment of the leaf mainspring with a coil spring, and deletion the grip safety.
Some pistols has a slotted backstrap to enable a wooden combination holster/shoulderstock to be fitted. The so-called 'new model' of 1904 in 9mm Parabellum was accepted by the German Navy and later the army and designated the P08. Thereafter, German military sales accounted for the vast majority of production.