sentences:  Encouraged in historical researches in Berlin by Leopold von Ranke, Kayserling turned his attention to the history and literature of the Jews of the Iberian Peninsula.In 1861 the government of Aargau appointed him rabbi of the two Swiss Jewish municipalities of Endingen and Lengnau in Surbtal, an office he held until 1870.During his residence in Switzerland he argued in favor of civil equality for his coreligionists, and also maintained contacts with high-ranking Swiss politicians such as Jakob Dubs, Emil Welti, and Augustin Keller.