1917 - 1918
ACT I - An Arcadian Landscape
Iolanthe, a fairy, has been banished by the Queen of Fairies because she has married a mortal, but at the intercession of her sister fairies, the Queen is persuaded to recall her. It appears that she had a son, Strephon, a "Shepherd of Arcadee", now about twenty-five years old, who is engaged to Phyllis, a Ward in Chancery. But the Lord Chancellor has other views about the disposition of his ward, and confesses to the other Peers that he is himself in love with Phyllis. The latter is summoned and confesses that she is in love with the "Shepherd of Arcadee", and Strephon, having been refused permission by the Lord Chancellor to marry his sweetheart, takes his sad case to his mother. In the interview, Iolanthe vaguely hints that there is a misty connection between her son and the Lord Chancellor. As Iolanthe and her son talk together, Lord Tolloller and Lord Mountararat, rivals for Phyllis' hand, appear with Phyllis between them. She listens in jealous dismay to the conversation between her lover and his fairymother, who appears to be about seventeen. In despair, she says that she will marry either of the two lords, Mountararat or Tolloller, leaving to them the decision as to which is shall be. There follows a chorus of the Peers who scoff at Strephon's absurd story that he, a man of twenty-five, has a mother who is only seventeen; but the Queen, furious at the Peers' incredulity, announces to them her fairyhood, and declares that Strephon shall avenge the insult to herself and to her subjects by going into Parliament.
ACT II - Palace Yard, Westminster
The second act opens with Private Willis on sentry duty before Westminster Hall. The fairies enter singing.
The Lord Chancellor meanwhile has allowed his legal mind to persuade his conscience that he himself may propose to one of his own wards; but at this point, Iolanthe makes an appeal on behalf of her son, reveals herself as the former wife of the Lord Chancellor, and Strephon is found to be his son. The complications arising out of this announcement are speedily and happily resolved by the legal dexterity of the Lord Chancellor.