 Virtually all international shipping that belonged to the confederation originated from either Prussia or the three Hanseatic city-states of Bremen, Hamburg, and Lübeck.Based on this, Adolf Soetbeer, secretary of the Hamburg Chamber of Commerce, suggested in the on 22 September 1866 that any planned flag should combine the colours of Prussia (black and white) with the Hanseatic colours (red and white).In the following year, the constitution of the North German Confederation was enacted, where a horizontal black-white-red tricolour was declared to be both the civil and war ensign.