After the First World War, Germany recognised Poland’s independence.  Europe’s new structure, enshrined in the Treaty of Versailles, resulted in East Prussia being accessible by land only via polish territory.  In order to create a direct link, the East Prussian Naval Service (“Seedienst Ostpreußen”) was set up.  In 1926, the Reich’s transport ministry put the “Preußen” (operated by Braeunlich) and the “Hansestadt Danzig” (operated by “Norddeutscher Lloyd”) into service. These were followed in 1935 by the “Tannenberg”, operated by the “Hamburg-America Line”.  Construction of the “Marienburg”, begun in 1939, was stopped. Not until 1950 she was finished in Wismar as a passenger motor ship.  Then she sailed to the USSR.