Type VII U-boats were the most common type of German World War II U-boat. The Type VII was based on earlier German submarine designs going back to the World War I Type UB III, designed through the Dutch dummy company Ingenieurskantoor voor Scheepsbouw den Haag (I.v.S) which was set up by Germany after World War I in order to maintain and develop German submarine technology and to circumvent the limitations set by the Treaty of Versailles, and was built by shipyards around the world.