Iolanthe

Twenty-five years before the setting of the opera, Iolanthe, a fairy, had committed the capital offence of marrying a mortal. The Queen of the Fairies had commuted the sentence to lifelong exile, on condition that Iolanthe left her husband and never saw him again.

Her son, Strephon, has grown up as a shepherd, half fairy, half mortal. Strephon loves Phyllis, who is a ward of the court of Chancery. She loves Strephon, but is unaware of his mixed origin. Meanwhile, the entire House of Lords is enamoured by Phyllis, especially the Lord Chancellor, her guardian. At the start of the opera, the fairies persuade the Queen to pardon Iolanthe, and she returns, introducing Strephon to her sisters. The Queen agrees to help when Strephon announces that he wishes to marry Phyllis, despite the Lord Chancellor’s refusal.

The House of Lords enter, and appeal to the Lord Chancellor to give her to whichever peer she chooses. Phyllis herself enters, and declines to marry a peer, announcing her intention to marry Strephon. The peers angrily refuse, and leave, taking Phyllis with them. Iolanthe enters and holds a tender conversation with her son. But, as she (like all fairies) looks like a girl of seventeen, Phyllis and the peers misinterpret the scene. They don’t believe that Strephon is being faithful, and Phyllis decides to marry one of two peers, Mountararat or Tolloller.

The fairies take revenge by sending Strephon to Parliament and casting a spell to make all the peers pass any bills that Strephon chooses, including entry depending on intelligence rather than class. The peers are terrified, and appeal to the fairies not to carry this out, but they refuse, so all angrily spurn each other.

A sentry ponders on duty. The peers are upset about Strephon’s success in Parliament, and appeal for the fairies to return things to normal. One of the lords sings in explanation. The fairies would like to oblige, as they have fallen in love with the peers themselves, but it is too late to stop Strephon. The Queen is shocked by the fairies’ feminine weakness, and while acknowledging the effect on her, of a nearby sentry, asserts that she remains strong.

Tolloller and Mountararat discover that if either marries Phyllis, then by family tradition, they must duel to the death. Both then renounce Phyllis in the name of friendship. Meanwhile, the Lord Chancellor has had a sleepless night, and eventually decides to marry Phyllis himself.

Strephon confesses to Phyllis that he is half fairy, and they decide to marry as soon as possible. They persuade Iolanthe to appeal to the Lord Chancellor on their behalf, and she does so, revealing that she is his wife. Thus, she again incurs the death penalty. Meanwhile, the other fairies have married the other peers, and so all should die. The Lord Chancellor suggests that by adding the word ‘don’t’ to the fairy law, the fairies would not have to die. To save her life, the Queen marries Private Willis, all the mortals are transformed into fairies, and they all fly away to Fairyland, leaving the House of Lords to be filled according to intelligence not birth. Sense, at last, prevails!