Sigismond Thalberg (8 January 1812 – 27 April 1871) was a composer and one of the most distinguished virtuoso pianists of the 19th century.He was born in Pâquis near Geneva, Switzerland, on 8 January 1812. According to legend, he was the illegitimate son of Prince Moritz Dietrichstein and Baroness Maria Julia Wetzlar von Plankenstern. However, according to his birth certificate, he was the son of Joseph Thalberg and Fortunée Stein who were both from Frankfurt-am-Main.[2