Gilbert wrote the words and Sullivan the music.

One of the operettas of Gilbert and Sullivan is titled "Princess Ida."

William S. Gilbert and Sir Arthur Sullivan.

The full names of the creative team responsible for the Gilbert and Sullivan operas were William Schwenk Gilbert and Arthur Seymour Sullivan. Gilbert generally signed his name as "WS Gilbert" and was know as "Schwenk" to his close relatives. Sullivan generally signed his name as "Arthur S. Sullivan" and never ussed just his three initials.

William Schwenk