Hamburg was a Free city since very early times. The city lost it's freedom during the occupation by the napoleonic troops and sufferered tremondously in that tim (the first decades in 1800) After the German-French war 1870-1871 the "German Reich" (the second) after the
Holy Roman Empire of German Nation was formed. This happened under the leadship of the Kingdom of Prussia. Hamburg was asked to enter that new Reich... and it agreed under one only condition:
To still be a Free Harbour in a part of Hamburg. This was re-confirmed by the European Authorities. Now Hamburg decided to reduce the territory of it's free harbour, desintegrated some parts. On this picture you see a part of the new "Harbour City" of Hamburg ... a new attraction for the City of Hamburg and it's visitors.