One of the (many) reasons to follow the WeaponsMan blog is that he keeps an eye out for neat auctions that, even if they cost the same as a new luxury sedan, provide great photos of rare or unique firearms. Most recently, Hognose has linked to an auction for a very rare MP.18-I, the first variant of the famous German MP.18 submachine gun (which, arguably, was the progenitor of the type):
We’ve featured an MP.18-II before, which is a later iteration of this exact same gun, with a magazine well reconfigured for straight magazines. (It led in turn to the MP.28, the Lanchester, and the Sten, by fairly direct process of derivation). But this gun, the MP.18-I, is the granddaddy of them all, and it could be yours.
It is certainly the first widely produced submachine gun, defined as a shoulder-fired infantry weapon firing a pistol cartridge with an automatic or select-fire mechanism. A blowback mechanism, it showed the way for many designs that would follow through three generations of submachine guns, until the rise of compact versions of intermediate-cartridge assault weapons would replace most of them.
Some would say it has a face only a mother could love:
The drum magazine is so odd looking because it was already in production for the Lange P.08, the “Artillery” Luger. Rather than try to design a thirtyish-round magazine, the engineers at Theodor Bergmann in the weapons-manufacturing center Suhl, Germany, did what many later gun designers would do and borrowed a proven one.
The only real predecessor to the MP.18 was the Villar-Perosa, which in its original configuration was an aircraft automatic gun chambered for pistol rounds, but later was applied to ground warfare as a light machine gun, and eventually as a portable automatic weapon. However, the Villar-Perosa, besides not being widely issued and not being purpose-designed as a submachine gun, was also much less influential; the descendants of the MP.18 being outright copied by many nations even as late as the 1940s.
I highly recommend readers follow the link and take a look at the auction itself; more pictures are available there (unfortunately in relatively low-res).