The Heckler & Koch MP5 is a 9mm submachine gun

Submachine gun

A submachine gun is an automatic carbine, designed to fire pistol cartridges. It combines the automatic fire of a machine gun with the cartridge of a pistol. The submachine gun was invented during World War I , but the apex of its use was during World War II when millions of the weapon type were...

 of German design, developed in the 1960s by a team of engineers from the German small arms

Small arms

Small arms is a term of art used by armed forces to denote infantry weapons an individual soldier may carry. The description is usually limited to revolvers, pistols, submachine guns, carbines, assault rifles, battle rifles, multiple barrel firearms, sniper rifles, squad automatic weapons, light...

 manufacturer Heckler & Koch GmbH (H&K)

Heckler & Koch

Heckler & Koch GmbH is a German defense manufacturing company that produces various small arms. Some of their products include the SA80, MP5 submachine gun, G3 automatic rifle, the G36 assault rifle, the HK 416, the MP7 personal defense weapon, the USP series of handguns, and the high-precision...

 of Oberndorf am Neckar

Oberndorf am Neckar

Oberndorf am Neckar is a town in the district of Rottweil, in Baden-Württemberg, Germany. It is situated on the river Neckar, 15 km north of Rottweil.-Geography:...

.

The MP5 is currently one of the most widely used submachine guns in the world, having been adopted by numerous military, law enforcement, intelligence and security organizations. In the 1990s, Heckler & Koch developed the Heckler & Koch UMP

Heckler & Koch UMP

The UMP is a submachine gun developed and manufactured by Heckler & Koch. The UMP has been adopted by various agencies such as the U.S. Customs and Border Protection...

, the MP5's successor, though both remain in production.
Heckler & Koch, encouraged by the success of the G3

Heckler & Koch G3

The G3 is a 7.62mm battle rifle developed in the 1950s by the German armament manufacturer Heckler & Koch GmbH in collaboration with the Spanish state-owned design and development agency CETME ....

 automatic rifle

Automatic rifle

Automatic rifle is a term generally used to describe a semi-automatic rifle chambered for a rifle cartridge, capable of delivering both semi- and full automatic fire...

, developed a family of small arms consisting of four types of firearms

Firearm

A firearm is a weapon that launches one, or many, projectile at high velocity through confined burning of a propellant. This subsonic burning process is technically known as deflagration, as opposed to supersonic combustion known as a detonation. In older firearms, the propellant was typically...

 (all based on a common G3 design layout and operating principle), where the first type was chambered in 7.62x51mm NATO, the second—using the 7.62x39mm M43 round, third—the intermediate 5.56x45mm NATO

5.56x45mm NATO

5.56×45mm NATO is a rifle cartridge developed in the United States and originally chambered in the M16 rifle. Under STANAG 4172, it is a standard cartridge for NATO forces as well as many non-NATO countries. It is derived from, but not identical to, the .223 Remington cartridge...

 caliber and the fourth type—chambering the 9x19mm Parabellum pistol

Pistol

When distinguished as a subset of handguns, a pistol is a handgun with a chamber that is integral with the barrel, as opposed to a revolver, wherein the chamber is separate from the barrel as a revolving cylinder. Typically, pistols have an effective range of about 100 feet.-History:The pistol...

 cartridge.