Erich von Stroheim directed and adapted the Franz Lehar operetta. A Crown Prince and his cousin fall in love with a beautiful dancer who, unable to marry the cousin, marries a wealthy baron and becomes a widow.
In the capital of a mountain kingdom from a great cathedral march King Nikita (George Fawcett,) Queen Milena (Josephine Crowell), and wealthy Baron Sadoja (Tully Marshall). The army is a day’s journey away. Crown Prince Mirko (Roy D’Arcy) gets out of a car and is saluted. He sees pigs and complains. Next in line to the throne is his cousin, Prince Danilo (John Gilbert). He keeps some pictures from Paris a friend showed him. He laughs at the pigs and notices the women. He examines his accomodations and relaxes with a drink. A woman comes in and fixes his pillow. He grabs her and kisses her. She slaps him and runs out. His servant was listening, and he kicks him in the butt. He looks out the window and sees the dancer, Sally O’Hara (Mae Murray), arrive. Men admire her legs, and she sticks out her tongue.
Danilo comes downstairs, and Sally sees him kiss a woman. He asks her if there is anything he can do. She is happy and shakes his hand. She says they are staying there one night and need a place. She introduces Danilo to their manager. The officers have taken all the rooms. Danilo says he could get some men to double up to give rooms to the ladies. He tells Sally she can use his room. He goes in the dining room and tells the men to double up. The Prince tells his cousin he is clever. Danilo does not want to be called “his Highness.” He goes back to Sally and introduces her to the men. The Prince kisses her hand and says she can use his room. Danilo sits between Sally and the Prince, who moves to her other side. Danilo uses his feet to touch her feet. Musicians play a waltz, and Danilo dances with Sally. When he kisses her, she hits him. He says it won’t stop him, and she warns him. He kisses her again, and she struggles. She feels sad, and he kisses her hand. She dances with him again.
The Prince talks with Sally and warns her that Danilo is a prince and unscrupulous with women. He loves for a day and rides away. Danilo comes back, and she says she learned he is a prince. He says the other man is the Crown Prince. She laughs, and Danilo dances with her.
At a theater the Manhattan Follies are starring Sally. She dances on stage with a man. The princes watch from a balcony with eyeglasses. Danilo has flowers and champagne brought to her dressing-room. He hides as the Prince comes in. The Prince reads the card with the flowers and rips it up. He takes out his own card and writes on the back, “To my sweet Irish Rose.” Danilo puts flypaper on the pillow as the Prince puts his head down on it.
Backstage Baron Sadoja meets Sally. The Prince is leaving her room, and Danilo has him take his card. The Baron offers Sally anything she asks if she will dine with him. She says she has an engagement. She introduces three women to him, and he looks at their feet. Sally sees the Prince, who offers her supper. She declines for the same reason. He says ladies usually accept his invitations. He warns her not to reject him. She tells him to get out of the way and goes in her dressing-room, where she finds Danilo. He closes the door, and she says he has nerve. He wants to take her to supper, but she has another engagement. He says very well and opens the bottle, pouring her a drink. She sees the roses and says she should thank him. She tells him to go because she has to get dressed. He says he is tired and wants to sleep, and he lays down on the bed.
At the place François people are having a good time, and the Prince enters that apartment. Danilo is in another apartment with Sally and mixes a drink. She says she has run away from many suppers hungry because her host got fresh. He asks if she always ran away, and she says yes. She asks him if he wants her to stay. He brings her a plate of food.
The Prince shoots his pistol to impress women.
Danilo is sitting next to her as she drinks wine and eats. He gets up and serves her a bowl of hot soup but spills it in her lap. He starts taking off her dress and suggests she can slip into a robe while it dries. She goes behind a curtain to change. There two blindfolded women are playing music on a large bed. Sally lays down, and Danilo peeks in. He sits next to her and takes her hand. He says they have two chaperones. He asks if her hands would scratch him if he took a kiss. She gets up to see if her dress is dry, but he holds her hand and kisses her. She struggles and says she hoped he was different. She cries. He asks if it is because she does not care enough. She says it is because she cares too much. She is sobbing, and he kneels down and kisses her hand.
In the other room the Prince and men leave the wild party.
Danilo tells Sally he brought her there as a whim, and now he does not want her ever to leave him. He says he loves her. The Prince and other men and women quietly sneak into the room. The Prince peeks through the curtain, and then it opens. Danilo stands up, and Sally looks at him. Danilo tells the men to be careful and not insult the future princess. Danilo calls the Prince a swine. The Prince bows and backs away, and they all leave the room. Sally says it has been a lie because he is a prince. He says he intended to tell her. She closes the curtain.
Outside the Prince kicks an old man on the ground.
Sally has put her dress and coat on and says goodbye to his Royal Highness and goes.
Danilo sits in his room. Suddenly he notices Sally laying on his bed and goes to her. He says she will always be his and kisses her.
At the palace King Nikita is angry at Danilo, who says he will marry Sally. The Prince is watching. The King asks what marriage has to do with love, and the Queen asks what love has to do with marriage. The Queen tells Danilo it is impossible for him to marry her, and Sally ought to know that. The King says one cannot marry every woman. The Prince says it is absurd to marry a cheap dancer. Danilo starts fighting the Prince, and the King restrains him. The King warns Danilo not to persist in folly, or he will make him a beggar. The King’s hand is hurt, and the Queen looks at it.
Sally is dressed as a bride and sees the Baron. She tells him she is going to be married. He asks if it is to Danilo. She sees the car has arrived in the rain. The Prince comes in and bows to her and the Baron. He asks to speak to her alone. The Baron asks if he is included, and the Prince nods.
Danilo is dressed, and the Queen pleads with him. She say a prince belongs to the state.
The Prince tells Sally to take off her dress because there will be no wedding.
The Queen explains to Danilo that a prince has a duty to his country. He is not the first royal to love and suffer. She says she was in love with a commoner. They have no choice.
The Prince tells Sally that the King wants her to leave the country forever. He says Danilo through him is giving her 50,000 francs to compensate her. She asks if Danilo knows of this and calls him a liar. She tells the Prince to leave before Danilo finds him there. He says she will have a long wait for Danilo and goes out.
Danilo pleads with the Queen that he cannot give her up, but she takes his letter to her and says she will send it by messenger.
Sally sits on her bed in her bridal gown at six o’clock. She laughs and tears off her veil.
The Queen rips the letter in half and puts it in a fireplace.
The Baron is telling Sally, who is laying on the floor, that as his wife she will have wealth and power. As his wife the King will have to invite her to the palace.
At the cathedral the Baron and Sally are being wedded.
That night Sally in a nightgown sits on a bed and looks at the ring on her finger. She cries.
Danilo is sitting at a table drinking with a woman. He throws his cup at the portrait of the King and cries.
The Baron in his robe is with Sally, but he collapses on the floor.
Sally, a doctor, and a nun are watching over the ill Baron, who lays in bed.
After a year of mourning and Paris, the widow returns to the mountain kingdom. The Prince tells Danilo and the Queen about the lady who charms Paris. She is called the merry widow, but they know her as the Irish Rose. Danilo tries to strangle him, and the Queen intervenes. The Prince says he is interested in the Baroness, and his father does not want her wealth to leave their kingdom. He says she may want to be the Crown Princess. Danilo breaks a vase on his head, and the Queen consoles him.
In Paris at Maxim’s people enjoy a show. Danilo is sitting with a woman who says she went through the same thing with her first sweetheart.
The Baroness hosts a party in Paris on June 1, 1923. She is cheerful in a black dress and bows to the Prince. She extends her hand, and he kisses it. He notices the diamonds in her necklace and says she is looking well. She says he is kind. Danilo comes in and is announced to the Baroness, who is sitting next to the Prince. A woman welcomes Danilo, and the Prince dances with Sally. Danilo sees her enjoying herself. Danilo bows to his cousin and says his business is not so urgent. Danilo bows to Sally. The “Siren Waltz” is played, and the Prince asks Sally if it reminds her of anything. She says she must finish the dance with Danilo, and he escorts her to the floor and dances with her. Others watch them. She says she is surprised he is still a bachelor. He must be wisely avoiding marriage. He says she has found consolation, and someone may marry her for her money. She asks if no one could love her for herself. He says her money would frighten off a man who is honorably in love with her. She questions whether he could be honorable about anything. They stop dancing, and she turns to the Prince and dances with him.
Sally and the Prince are riding horses with others. The Prince says he loves her and wants her to be his wife. She suggests he should not propose without asking whether it would be impertinent. She sees Danilo laying on the ground with a bottle asleep. They get off their horses, and the Prince pokes him with his stick. Danilo awakes and is greeted by his cousin. Danilo is helped up and bows to Sally. He realizes his name is not as alluring as the Prince’s. She suggests he take his failure in a better spirit. He says he has not failed because he has not attempted. She is glad he did not waste his time. She says she just became engaged to Prince Mirko. Danilo laughs, and the Prince says she wants him to be best man. Danilo assaults the Prince and knocks him down. The Prince stands up and says for that he will die. Danilo accepts the challenge and bows to them.
At Maxim’s Danilo is dancing with a woman and is drunk. He is advised to get some sleep so he will be able to shoot; but he goes on drinking. Sally comes in, and he goes to her and asks why she is there at that hour. She wants to speak to him alone. They sit at a table apart. She begs him not to go on with the duel. He asks if she is afraid for him. Does she love him that much? He assumes she came to beg him for his life. He says it is an affair of honor and that he is the challenged party. He helps her with her coat, and she leaves.
The duel follows the rules of Barbasetti. They prepare and are given pistols. Sally is coming in a car. The Prince declines to be reconciled, and so does Danilo. They raise their guns, and Danilo fires into the air. The Prince shoots Danilo in the chest, and he falls and is attended to by doctors. The Prince admires his pistol. Sally comes running up to Danilo, who says he saved him for her. She cries and kisses him.
King Nikita died, and the Prince marches in the funeral. An assassin shoots the Prince and escapes. The Queen kisses the Prince.
In the spring Danilo wakes up in bed and sees Sally. She comforts him, and he asks why she is there. She says she loves him and has always loved him. A messenger informs them that the Crown Prince was assassinated. Danilo is now the Crown Prince. The King is dead, and a new King reigns.
In the cathedral King Danilo crowns Sally queen. He calls her Sally O’Hara, and she calls him Majesty; but he says he is plain Danilo Petrovich.
This romantic drama contrasts the sincere love the amorous Danilo has for Sally with the cruelty and selfishness of the Prince. Danilo is passionate and easily provoked to fight while Sally knows she has to fight off men to protect her honor. After being heartbroken in being unable to marry a prince, she lowers her standards and accepts other men.