It is noted in 1612 in in the Schleswig State Archive that R. was "Schutzjude", i.e. under the protection of the Count of Schauemburg. He was "Parness Unamhig", i.e. a sort of community leader. In 1640 he was sworn in by Danish King Christian IV and made responsible for law and order in the Jewish community. R's relatives also lived in Berlin, Dessau and Hamburg.