Princess Ida is based on Tennyson's The Princess. It is the only operetta that W.S. Gilbert wrote in blank verse, and it is the only Gilbert & Sullivan operetta in three acts.
The operetta satirizes feminism and women's colleges, both of which were controversial topics in conservative Victorian England.
The Plot
Warning: Wikipedia contains spoilers!
Princess Ida is a young woman who writes off men entirely and forms a women's college where no man is ever to set foot. The operetta opens on the day that she is supposed to meet the man to whom she was betrothed in infancy, but she ignores her duty and remains at her college.
Her prince, Hilarion, has never met her, but is in love with her anyway. Therefore, he and two of his friends invade Ida's college, laughing at the very concept: "A woman's college -- maddest folly going!"
In the end, Ida is persuaded to wed her prince when Hilarion's father, King Hildebrand, presents her with the following argument:
If you enlist all women in your cause,
And make them all abjure tyrannic Man,
The obvious question then arises, "How
Is this Posterity to be provided?"
She replies,
I never thought of that!Princess Ida is an interesting operetta with lovely music. However, between the comments made by characters in the operetta and its simplistic resolution, it is clearly a backlash against feminism's earliest incarnation.