arb und Grey C , In the German Empire ,a Federal Empire , existed four Kingdoms,Prussia Bavaria Saxony and Wurtemberg . each with the respective King. But existed also the Great Duchies , Baden Hesse Darmstadt, Mecklenburg Schwerin and Mecklenburg Strelitz , Saxe Weimar and Oldenburg. each with their Great Duke ,Gross herzog , that counts as a Sovereign. existed five Duchies and seven Principalties ,each with a Duke or a Prince , and finally there were three Free Cities , Hamburg Lubeck and Bremen that were Republics with a President of the Senat ,at the head. contrary to whar arb thinks in the German Empire the Grossherzogin of Hesse counted as a Sovereign .