Once upon a time, not so very long ago, before the world was divided into armed camps bent on mutual self-destruction, European stagecraft was one gigantic operetta. In France, the court of Napoleon III and Eugenie was playing out its own version of The Chocolate Soldier. In pre-Bismarck Germany, there were innumerable small states, each as pompous and irresponsible as the Bavaria of Mad Ludwig II.

The Grand Duchy of Gerolstein is, indeed, modeled after such states with their predilection for uniforms, ribbons, and titles.

Gerolstein is ruled by a Grand Duchess who ascended the throne at an early age. Her sole tutors have been the diplomat Baron Puck and General of the Armies Bourn. Puck has arranged a war to divert his young charge from the “dangerous” tendencies peculiar to a girl of twenty years.

A grand review of the Army is about to be held. In the ranks is a recruit by the name of Fritz. He has already aroused the jealousy of Bourn by winning the affections of a peasant girl, Wanda, with whom Bourn is infatuated. The Grand Duchess arrives to review her troops and to bid them farewell before battle. Fritz incurs further disfavor with his commanding officer by attracting the attention of the Grand Duchess herself, who, to the dismay of the General, calls him out of the ranks, enters into conversation with him and invites him to sing the regimental song with her. In a matter of moments, Fritz is promoted to corporal, sergeant, lieutenant, and, finally, captain! The Duchess withdraws to her state tent to contemplate battle plans. Before receiving her advisors, she grants an interview to Prince Paul, the heir to a neighboring duchy. After six unsuccessful months, this is his first opportunity to press his marriage suit. Her Highness will have none of it. To pacify him, she allows him to remain for the war council. Bourn submits his plans. Fritz declares them utter nonsense, and is given leave by the Duchess to state his own views, to which Bourn and Puck object that, being neither a commanding officer nor a nobleman, he must not be heard. The Duchess, thereupon, elevates Fritz to a general’s rank and creates him a baron. Fritz offers a plan of charming simplicity which so delights her Highness that she invests him with the supreme command, and submits the conduct of the campaign to his skill and courage. As Bourn, Puck, and Paul plot revenge, Fritz is presented with the symbol of his rank, the sabre of the Duchess’ father. The troops depart for glorious battle.

The enemy has been vanquished. The ladies-in-waiting eagerly await the return of their beloved heroes. A public reception is held in the State Chamber in honor of Fritz’ triumphant return. He regales his avid audience with his exciting tale of victory. Her Highness dismisses the court and arranges for a tête-a- tête with Fritz. Under the guise of representing one of her ladies-in-waiting, the Duchess confesses her passion for him. He, however, is too dense, or too preoccupied with thoughts of his Wanda to understand this declaration of love. The Grand Duchess, mortified at this seeming indifference, decides to gain revenge. Overhearing a conspiracy between Bourn, Puck, and Paul against the life of her supposed favorite, she bursts in upon the conspirators and offers to join in their plot, a proposal which is gleefully accepted. In the past, the Duchess’ ancestress, the Grand Duchess Victorine had assigned an apartment to her favorite, Count Max of Sedlitz-Calembourg in the Right Wing of the castle where he was subsequently murdered by ten assassins. Since that time, the room has been known as the Red Chambre. Fritz is to be quartered there and done in, à la Max.

In the Red Chambre, the conspirators are joined by Baron Grog, emissary of Prince Paul’s father. He has the good fortune to captivate the fancy of the Grand Duchess, who consents to marry Paul in exchange for Grog’s willingness to remain in Gerolstein. The Grand Duchess, to avoid bloodshed on her wedding day, countermands the assassination of Fritz and allows him to marry Wanda. The conspirators are permitted to play a practical joke upon Fritz on his wedding night: a series of serenades interrupt the consummation of the marriage, and a false message summons Fritz to his military command.

At the encampment, the union of the Grand Duchess with Prince Paul is being celebrated. Fritz bursts upon the scene in a dilapidated state, the emblems of his authority in a most battered condition. Through mistaken identity (engineered by Bourn), Fritz has been waylaid by a jealous husband. The Grand Duchess, incensed by this degradation of her former favorite, deprives him of his command and reinstates General Bourn to his former rank. Baron Puck receives the cherished sabre of her father. Fritz and Wanda decide they can best serve their country by producing offspring. And the Grand Duchess anticipates the pleasure of her new ménage.