The Duchess of Dantzic is a comic opera in three acts, set in Paris, with music by Ivan Caryll and a book and lyrics by Henry Hamilton, based on the play Madame Sans-Gêne by Victorien Sardou and Émile Moreau. Additional lyrics by Adrian Ross. The story concerns Napoleon I and a laundress, Catherine Üpscher, who marries Marshal Lefebvre and becomes a Duchess.
The opera was first produced in London at the Lyric Theatre in 1903 and ran for 236 performances. Subsequently, it enjoyed a successful New York production and other productions around the world, and was revived in London and performed regularly by amateur theatre groups, particularly in Britain, until the 1950s.
After composing a few comic operas early in his career, Caryll became extraordinarily successful in the 1890s, writing the music to hit musical comedies produced by George Edwardes, including The Shop Girl (1894), The Gay Parisienne (1896), The Circus Girl (1896) and A Runaway Girl (1898). After the turn of the century, he continued to write some of the most successful musical comedy scores of the era, including The Messenger Boy (1900), The Toreador (1901), The Girl From Kays (1902), The Earl and the Girl (1903) and The Orchid (1903). With The Duchess of Dantzic, he turned back to comic opera. Although the piece met with success, it was not the kind of blockbuster hit that the above-mentioned musical comedies were.