The landing craft of the Kriegsmarine are a often neglected part of German naval history, although the over 700 crafts build played multiple roles during World War II.
During the invasion of Norway in 1940 (Operation Weserübung), the Kriegsmarine did not have specialized landing crafts, instead destroyers, cruisers and torpedo boats were used. During the following planning operation for the invasion of England (Seelöwe) it got obvious that it could not be archived without such crafts. Since the development of real landing crafts would take too long, many river boat and merchant ships were provisionally modified for this role and the designs of real landing crafts was started.
Operation Sealion never took place, but the so called Marinefährprahme (MFP) were build. They proved to be as vehicles with a universal use - besides transport and supply operations in all theaters of war, they could be operating as gun boats, mine layers or Sperrbrecher.