Utopia Ltd was the lastreasonably successful G & S operetta, A satire on the concept of the perfect society based on a South-Sea Island ruled over by King Paramount.
The King's daughter, Zara, has been educated at Girton, and returns home with six pillars of the English establishment to re-model the countyry on the lines of England. These worthies included Captain Corcoran (HMS Pinafore).
Gilbert takes the opportunity to fire with all barrels at all the things about England that he would have liked to reform.
It was completed with difficulty, as Sullivan was seriously ill, and at one stage expected to die. It opened in London on the 7th October 1893, and ran for 245 performances.
It flopped in America, and has not been much performed since.
The Grand Duke followed in 1895 which only ran for 123 performances.
Thespis, the first production, was undoubtedly the least successful,
I can find no record of the number of performances, but it is estimated as no more than 64, the score was 'lost'.
One song 'Climbing over Roccy Mountain' was re-cycled in 'Pirates'.
All the above cribbed from Leslie Bailey, 'The Gilbert & Sullivan Book'

FC