A British comic opera, the last, longest, most complex collaboration of the Victorian dramatic duo Gilbert and Sullivan. Debuted in March of 1896, it is set in the german town of Pfennig-Halbpfennig, which is ruled by Grand Duke Rudolph, a cheapskate hypochondriac. He is planning to get married to another cheap patrician, the Baroness Von Krakenfeldt, and so has engaged all the priests in the town for the occasion. This means that Ludwig, a comic actor, and his actress lady love, Lisa, cannot be married until Rudolph's wedding is done.
Ludwig and Lisa are part of a scheme to overthrow the Grand Duke and replace him with their company's manager, Ernst Dummkopf, who has promised to give each actor a place in his court according to their position in his company (by which he means to make the leading actress, Julia Jellicoe, his Grand Duchess). One may know a fellow conspirator by their giving of the secret sign; eating a sausage roll. The conspirators are, after six month's planning, very sick of these pastries, but such are the sacrifices of revolution.
Ludwig, on the morning the play begins, spots a man who he thinks is a conspirator, and gives the secret sign. The fellow responds by eating three sausage rolls, and Ludwig spills all the details of the plot. However, he only just finishes when he realizes that nobody involved with the conspiracy WOULD eat three sausage rolls! Horror! He then realizes that the stranger is the Grand Duke's detective, who will surely report the plot!
The conspirators panic, until a notary informs them of an old law; the Statutory Duel. The duelists draw cards, the higher card wins, and the lower card is legally dead. The winner assumes the loser's responsibilities. The law, 100 years old, is set to expire tomorrow. Ernst and Ludwig duel; Ludwig draws an ace, winning the duel, and so must go to the Grand Duke and confess to the plot, taking the blame for the conspiracy and losing his life.
As Ludwig comes to Rudolph, he finds Rudolph hysterical with grief, because he has learned people are plotting to overthrow him. Ludwig, thinking fast, arranges to stage a duel with Rudolph, and thus become Grand Duke for a day. Then, when the law expires, Ruldoph can return to his post, the conspiracy having been unearthed. They duel; Rudolph draws a king, Ludwig, again, an ace. Ludwig is Grand Duke. However, no sooner has he been successful than he renews the law of Statutory Dueling for another 100 years!
Eager to be a good ruler, Ludwig decides to take his theater company's costumes from Troilus and Cressida to revive the ancient traditions of Athens. However, he cannot marry his beloved Lisa, but must fulfill the obligation he inherited from Ernst and make Julia his duchess! Left with no other choice, he marries Julia. Then, as they celebrate the wedding by getting amazingly drunk, the Baroness von Krakenfeldt returns, stating that, since Ludwig inherited the position of Grand Duke from Rudolph, he also inherited the obligation to marry her. As if this were not enough, the Prince of Monte Carlo shows up with his daughter, to whom Grand Duke Rudolph was engaged as a child, and so Ludwig has been vicariously married to all along.
Things look bad. However, Rudolph and Ernst, along with the notary, return at this moment to say that they have gone over the law and found that the ace is actually the LOWEST card, counting as a one! Thus, Ludwig has been dead for two days, Rudolph is still Grand Duke, the law was never renewed, and things return to exactly the way they were. After being legally dead, Ernst has lost his desire to be ruler and contents himself with wedding Julia. Rudolph, happy to be Grand Duke again, gladly marries the fabulously wealthy Princess of Monte Carlo. Ludwig marries Lisa. The Baroness gets drunk off her arse. Everyone lives happily ever after.