Rusalka is a tragic opera in three acts by the Czech composer Antonin Dvorak (see Dvorak, Antonin). Its Czech libretto (text), by the Czech writer Jaroslav Kvapil, is based mainly on the fairy tales "Undine" by the German novelist Friedrich de La Motte Fouque and "The Little Mermaid" by the Danish author Hans Christian Andersen. Rusalka was first staged in Prague, now in the Czech Republic, on March 31, 1901.