Claim: Heinrich Sahm, a German Lawyer, also served as mayor of Danzig and, after it became the Free City of Danzig, the first President of the Senate.
Evidence: Heinrich Friedrich Wilhelm Martin Sahm (12 September 1877 – 3 October 1939) was a German lawyer, mayor and statesman from the Free City of Danzig. In 1919 he was elected mayor of Danzig (Gdańsk), a city that had formerly belonged to the German Empire. In the same year Danzig and the surrounding territory was to be severed from Germany and turned into a city-state according to the Versailles treaty. After the establishment of the Free City of Danzig in 1920, Sahm became first President of the Senate, the de facto head of state beneath the High Commissioner of the League of Nations.