The Walther P38 is a 9 mm semi-automatic pistol that was developed by Walther as the service pistol

Service pistol

A service pistol is any handgun issued to military personnel.Typically service pistols are revolvers or semi-automatic pistols issued to officers, non-commissioned officers and rear-echelon support personnel for self defense, though service pistols may also be issued to special forces as a backup...

 of the Wehrmacht

Wehrmacht

The Wehrmacht – from , to defend and , the might/power) were the unified armed forces of Nazi Germany from 1935 to 1945. It consisted of the Heer , the Kriegsmarine and the Luftwaffe .-Origin and use of the term:...

 at the beginning of World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

. It was intended to replace the costly Luger P08

Luger pistol

The Pistole Parabellum 1908 or Parabellum-Pistole , popularly known as the Luger, is a toggle-locked recoil-operated semi-automatic pistol. The design was patented by Georg J...

, the production of which was scheduled to end in 1942.
The P38 concept was accepted by the German military in 1938 but production of actual prototype ("Test") pistols did not begin until late 1939. Walther began manufacture at their plant in Zella-Mehlis

Zella-Mehlis

Zella-Mehlis is a town in the Schmalkalden-Meiningen district, in Thuringia, Germany. It is situated in the Thuringian Forest, 5 km north of Suhl, and 20 km east of Meiningen. The town of Zella-Mehlis is the site of the original Walther arms weapons factory. It remained there until the...

 and produced three series of "Test" pistols, designated by a "0" prefix to the serial number.