Born Marguerite de Valois at the royal Château de Saint-Germain-en-Laye and nicknamed Margot by her brothers, she was the daughter of Henry II and Catherine de' Medici. Three of her brothers became kings of France: Francis II, Charles IX and Henry III. Her sister, Élisabeth de Valois, became the third wife of King Philip II of Spain.
Marguerite was forced to marry Henry de Bourbon, the son of Jeanne d'Albret, the Protestant Queen of Navarre, in a marriage that was designed to reunite family ties and create harmony between Catholics and Huguenots. Although Henry's mother opposed the marriage, many of her nobles supported it, and the marriage was arranged. Jeanne d'Albret died under suspicious circumstances before the marriage could take place; some suspected that a pair of gloves sent to Jeanne as a wedding gift from Catherine de' Medici had been poisoned.
On 18 August 1572, the 19-year-old Marguerite married Henri de Bourbon, who had become King of Navarre upon the death of his mother.
Just six days after the wedding, on Saint Bartholomew's Day, a massacre of Huguenots was conducted by Parisian mobs.
Marguerite has been credited with saving the lives of several prominent Protestants (including her husband) during the massacre, by keeping them in her rooms and refusing to admit the assassins, which included her lover, Henri de Guise. For her pains, she was confined to the Louvre by her mother. Henry of Navarre, too, was placed under house arrest and had to feign conversion to Catholicism.
After more than three years of confinement at court, Henry escaped Paris in 1576, leaving his wife behind. Finally granted permission to return to her husband in Navarre, for the next three and a half years Marguerite and her husband lived in Pau. Both openly kept other lovers, and they quarrelled frequently.
After an illness in 1582, Queen Marguerite returned to the court of her brother, Henry III, in Paris. But Henry III was soon scandalized by her reputation and forced her to leave the court. After long negotiations, she was allowed to return to her husband's court in Navarre, but she received an icy reception. Determined to overcome her difficulties, Queen Marguerite masterminded a coup d'état and seized power over Agen, one of her appanages. After several months of fortifying the city, the citizens of Agen revolted and Queen Marguerite fled to the castle of Carlat. In 1586, she was imprisoned by her brother Henri III in the castle of Usson, in Auvergne, where she spent eighteen years.
In 1589, her husband succeeded to the throne of France as Henry IV, though he was not accepted by most of the Catholic population until he converted to that faith four years later. Henry continued to keep mistresses, most notably Gabrielle d'Estrées from 1591 to 1599, who bore him four children. Negotiations to dissolve the marriage were entered in 1592 and concluded in 1599 with an agreement that allowed her to maintain the title of queen. She settled her household on the Left Bank of the Seine, in the Hostel de la Reyne Margueritte.
During this time, Marguerite wrote her memoirs consisting of a succession of stories relating to the affairs of her brothers Charles IX and Henri III with her former husband Henry IV. The memoirs were published posthumously in 1628 and scandalised the population. Marguerite took many lovers both during her marriage, and after divorcing. Most notable were Joseph Boniface de La Môle, Jacques de Harlay, Seigneur de Chanvallon and Louis de Bussy d'Amboise.
Reconciled to her former husband and his second wife, Marie de Medici, Queen Marguerite returned to Paris and established herself as a mentor of the arts and benefactress of the poor. She often helped plan events at court and nurtured the children of Henry IV and Marie. Marguerite died in her private residence, the Hôtel de la Reine Marguerite in Paris, on 27 May 1615, and was buried in the Chapel of the Valois.
Alexandre Dumas, père's novel Queen Margot ("La Rei