Karl Sieveking, born 1 November 1787 in Hamburg, died 30 June 30 1847, was a Syndicus of Hamburg, diplomat, politician, patron of the arts and philanthropist. The four syndics sat in the Senate with the senators and took part in the debates, but had no vote. The office, at that time, was somewhat analogous to that of a cabinet minister (which did not exist as such in Hamburg). To them were entrusted all important negotiations, and the preparation of every legislative enactment.A syndicus ranked between a mayor and a senator and had the title "Magnificence". Sieveking was one of the most influential figures in Hamburg in the first half of the 19th century. Among the many traces he left behind in his hometown include the Rauhes Haus, the Kunstverein and the former country estate Hammer Park.