Her peaceful life in the country is disrupted when two great men are riding across the estate and see her in a boat on the river. One is her former suitor Guise, who has not stopped wanting her, and the other is the heir to the throne, the Duke of Anjou. Determined to see more of her, Anjou invites himself and Guise to the castle, where Montpensier arrives as well to be their host. At the dinner table, the princess is surrounded by four men who desire her and, in the case of Montpensier and Guise, hate each other. When the Montpensiers are summoned to Paris, Guise tells Renée he still loves her while Anjou tries to win her favour. At a masked ball, the princess thinks she is talking to Guise and says how Anjou is pursuing her. In fact the man she whispered to was Anjou, who forms a deep hatred for Guise.
Suspicious, Montpensier orders his wife back to their castle and she then prevails on Chabanes, whom everybody trusts, to carry messages to and from Guise. This becomes dangerous when Montpensier returns to the castle. Through Chabanes, Guise says he must see Renée face to face and, when she agrees, Chabanes smuggles him into her bedroom. A noise wakes up Montpensier who, finding Renée 's bedroom door locked, in fury starts breaking it down. When he bursts in, he finds Chabanes standing calmly and the princess fainted on the tiled floor. Chabanes says things are not what they seem and that Renée, in a state of nervous collapse, needs putting to bed.
She never recovers from the shock. Chabanes is murdered by followers of Guise in the St. Bartholomew's Day massacre and Guise swiftly makes an advantageous marriage. When the princess hears the news, she dies unable to overcome the grief of having lost the respect of her husband, the heart of her lover, and the best friend there ever was.
The party then travels to Paris, where Montpensier surprises Guise and Marie talking intimately together. Swords are again drawn. This time it is Anjou who breaks up the fight. Guise then catches Marie on a staircase and starts kissing her, but she breaks away. She confides in Chabannes, who advises her to keep well clear of Guise. Guise, he warns her, is simultaneously courting another woman, the royal princess Marguerite of Valois, sister of Anjou.
At the start, there is no court and no princess. An older man, Comte de Chabannes (Lambert Wilson) is having a bad day on the battlefield, during which he kills innocents, and, disgusted, flees the battlefield. This leaves the Comte a man without a support from either side, a traitor to both although he ironically seems more religious than either.
The titular princess, begins the movie as Marie de Mézieres , the heiress of a great fortune and engaged to the brother of her true love, Henri Duc de Guise (Gaspard Ulliel). Henri de Guise does not take great pains to disguise his desire for Marie. Is this the nature of true love or the lack of respect brought by a selfish lustful man?
The other day there was a masked and costumed ball,
but only for the family and the intimate court circle--the
princesses and ladies of honour. M. de Joinville
appeared all in rags, in complete Chicard costume. He was
extravagantly gay and danced a thousand unheard-of
dances. These capers, prohibited elsewhere, rendered the
Queen thoughtful. "Wherever did he learn all this?"
she asked, and added: "What naughty dances! Fie!"
Then she murmured: "How graceful he is!"
The guests arrived at half-past eight. The Duke de
Nemours lives on the first floor of the Pavilion de Marsan,
over the apartments of the Duchess d'Orleans. The guests
waited in a first salon until the doors of the grand salon
were opened, the women seated, the men standing. As
soon as the prince and princess appeared the doors were
thrown wide open and everybody went in. This grand salon
is a very fine room. The ceiling is evidently of the time
of Louis XIV. The wails are hung with green damask
striped with gold. The inner window curtains are of red
damask. The furniture is in green and gold damask. The
ensemble is royal.
The King and Queen of the Belgians were at this
concert. The Duke de Nemours entered with the Queen, his
sister, upon his arm, the King giving his arm to the
Duchess de Nemours. Mmes. d'Aumale and de Montpensier
followed. The Queen of the Belgians resembles
the Queen of the French, save in the matter of age. She
wore a sky-blue toque, Mme. d'Aumale a wreath of roses,
Mme. de Montpensier a diadem of diamonds, Mme. de Nemours
her golden hair. The four princesses sat in high-backed
chairs opposite the piano; all the other women sat
behind them; the men were in the rear, filling the doorway
and the first salon. The King of the Belgians has a rather
handsome and grave face, and a delicate and agreeable
smile; he was seated to the left of the princesses.