Zara's Kingdom is a South Pacific kingdom ruled by British-educated Princess Zara and a sextet of exemplary Englishmen, including Captain Corcoran who'd previously served aboard Her Majesty's Ship Pinafore.
Zara's Kingdom, Princess Zara, and Captain Corcoran are from Gilbert & Sullivan's Utopia Limited; or, The Flowers of Progress (1893). The H.M.S. Pinafore is a reference to Gilbert & Sullivan's H.M.S. Pinafore (1878).