After much talk of other matches came to nothing, Wilhelmine was eventually married in 1731 to her
Hohenzollern kinsman,
Frederick, Margrave of Brandenburg-Bayreuth. Frederick had been engaged to Wilhelmine's younger sister,
Sophie, but at the last moment King Frederick William I decided to replace her with Wilhelmine. The groom was not consulted in this decision. This marriage was only accepted by Wilhelmine under threats from her father and with a view to lightening
her brother's disgrace. It was initially a happy marriage, but was eventually clouded first by limited financial resources and then by a love affair of the future
Margrave with
Dorothea von Marwitz, whose rise as an official mistress at the court of Bayreuth was bitterly resented by her brother Frederick the Great and caused an estrangement of some three years between him and Wilhelmine. Wilhelmine's only child was
Elisabeth Fredericka Sophie of Brandenburg-Bayreuth, born on August 30, 1732. Described by
Casanova as the most beautiful princess in Germany, she was married to
Karl Eugen, Duke of Württemberg, in 1748. She died on 6 April 1780 without surviving children., built in her memory When Wilhelmine's spouse came into his inheritance in 1735, the pair set about making Bayreuth a miniature
Versailles. Their building projects included the rebuilding of their summer residence (now part of the
Hermitage Museum (Bayreuth)); the rebuilding of the great Bayreuth opera house; the building of a second, new opera house; the building of a theater; and the reconstruction of the Bayreuth palace. The so-called
Bayreuth Rococo style of architecture is renowned even today. The pair also founded the
University of Erlangen. All of these ambitious undertakings pushed the court to the verge of
bankruptcy. The margravine made Bayreuth one of the chief intellectual centers of the
Holy Roman Empire, surrounding herself with a court of wits and artists that accrued added prestige from the occasional visits of
Voltaire and Frederick the Great. Wilhelmine's brother Frederick granted her an allowance in exchange for troops, following the same procedure with her sisters. With the outbreak of the
Seven Years' War, Wilhelmine's interests shifted from
dilettantism to diplomacy. Austrian diplomats were trying to influence the court of Bayreuth to take their side against Prussia. In September 1745, during the Silesian war, Wilhelmine met with Maria Theresa of Austria. This almost destroyed her intimate relationship with her brother. In 1750 Wilhelmine visited the Prussian court for several weeks and met famous contemporaries such as Voltaire, Maupertuis and La Mettrie. In June 1754, the siblings met for the last time, after which Frederick swore her his eternal loyalty. She acted as eyes and ears for her brother in southern Germany until her death at
Bayreuth on 14 October 1758, the day of Frederick's defeat by the
Austrian forces of
Leopold Josef Graf Daun at the
Battle of Hochkirch. Although Frederick had lost many friends and family to death throughout his life, Wilhelmine's hit him the hardest. He suffered from severe illness for a week following news of Wilhelmine's death and fell into a depression from which he never fully recovered. On the tenth anniversary of her death, her devastated brother had the
Temple of Friendship built at
Sanssouci in her memory. == Works ==