 Therefore, the North German and eventually Imperial German flags prominently featured the Prussian colours (black and white) as well as symbols like the Prussian eagle and the Iron Cross.And while seafaring was the traditional domain of the Hanse in Germany, virtually all of the 19th century German coastline (including the North Sea coast) and naval power belonged to Prussia after the decisive victory in 1866.Prince Adalbert of Prussia, the commander-in-chief of the North German Navy, was commissioned with finding the design of the new war ensign.