What is "erminie"

Erminie is a comic opera in two acts composed by Edward Jakobowski with a libretto by Claxson Bellamy and Harry Paulton, based loosely on Charles Selby's 1834 English translation of the French melodrama, Robert Macaire. The piece first played in Birmingham, England, and then in London in 1885, and enjoyed unusual international success that endured well into the twentieth century.