Iolanthe
Iolanthe, or "The Peer and the Peri," is a comic Gilbert and Sullivan operetta in two acts. The music is by Sir Arthur S. Sullivan and the libretto by Sir William S. Gilbert. It was first produced in London, November 1882.
Plot
Act I: At the impositioning of several of the fairies, the Queen of the Faries agrees to pardon the fairy Iolanthe for her past sin - that of having married a mortal. Iolanthe rises from the stream that has been her prison, and is surrounded by her former friends. She tells them of her son, the half-fairy half-mortal Strephon. When her friends finally depart, Iolanthe meets Strephon, and hears from him of his love for the Lord Chancellor's current ward, Phyllis. Strephon is despondent, as the Lord Chancellor has forbid them to marry - partly because he himself wishes to marry Phyllis. Iolanthe promises to help her son, in part by arranging for him to become a Member of Parliament. Phyllis comes by, and she and Strephon share a moment of tenderness.
As they leave, a cadre of the peers of the realm arrive. They are all, it turns out, in love with Phyllis, and appeal to the Lord Chancellor to settle the matter. They send for Phyllis, who declares that she won't marry anyone but Strephon. The peers immediately separate the two lovers. Strephon calls on Iolanthe for help; she appears, and in her affection for her son, the peers see an opportunity. They tell Phyllis that Strephon is being affectionate with an (apparently) young woman, and scoff at claims that Iolanthe is Strephon's mother. Phyllis is convinced, and rejects Strephon for this "infidelity." Enraged, the faries pronounce a curse on the peers: Strephon shall not only join their number, but will be able to get any bill he proposes passed. He is to be the instrument of fairy vengeance, disrupting Parliament and causing trouble.
Act II: The Queen has led her fairies to Westminster, where she comes because she's somewhat smitten with Private Willis of the Guard there.