Sigismond Thalberg (January 8, 1812 – April 27, 1871) was a Swiss composer and one of the most distinguished virtuoso pianists of the 19th century. Sigismond Thalberg was born in Pâquis near Geneva, Switzerland, on January 8, 1812. According to his birth certificate, he was the son of "Joseph Thalberg" and "Fortunée Stein", both from Frankfurt-am-Main, but the names in the birth certificate are now regarded as fictitious. For reasons of Thalberg's illegitimate birth, during his lifetime it was common use not to call his parents true names.