In May 1872 a ten-year building programme was instituted to modernise the fleet. This called for eight armoured frigates, six armoured corvettes, twenty light corvettes, seven monitors, two floating batteries, six avisos, eighteen gunboats and twenty-eight torpedo boats, at an estimated cost of 220 million gold marks. The building plan had to be approved by the Reichstag, which controlled the allocation of funds, although one-quarter of the money came from French war reparations.[2]