Founder of the renowned Arnstein dynasty of dominant court financiers in Vienna in the 18th and first half of 19th century. The Arnsteins married into other leading Jewish families, such as Gomperz, Itzig, Mendelssohn and Pereira.
Born in Arnstein and settled in Vienna in 1705. He worked for Samson Wertheimer, and executed important financial transactions for Wertheimer’s firm, eventually becoming an associate. He also worked independently, as food supplier to the Royal Court and Military Establishment. In 1736 he used his influence to prevent the expulsion of the Jews from Vienna.