He was born 6 March 1823 at Stuttgart, as HRH Charles Frederick Alexander, Crown Prince of Württemberg the son of William I, King of Württemberg (1781–1864) and his third wife (and first cousin) Pauline Therese of Württemberg (1800–1873). He studied in Berlin and Tübingen.
On 13 July 1846 he married Olga Nikolaievna of Russia, daughter of Tsar Nicholas I and Charlotte of Prussia. Charlotte was a daughter of Frederick William III of Prussia and Louise of Mecklenburg-Strelitz. She took the name Alexandra upon her marriage.
Karl acceded to his father’s throne in 1864, making Olga Queen of Württemberg
The couple had no children, perhaps because of Karl’s suspected homosexuality, although there were rumors (perhaps simply just that, rumors) that the king was having an affair with the notorious American Creole actress AdahMenken who was supposedly his morganatic bride . Karl became the object of scandal several times for his closeness with various men. The most notorious of these was the American Charles Woodcock, a former chamberlain whom Karl elevated to Baron Savage in 1888. Karl and Charles became inseparable, going so far as to appear together in public dressed identically. The resulting outcry forced Karl to renounce his favorite. Woodcock returned to America, and Karl found private consolation some years later with the technical director of the royal theater, Wilhelm George.
Princess Pauline Clémentine von Metternich – Winneburg zu Beilstein née Countess Pauline Clémentine Marie Walburga Sándor de Szlavnicza (February 25, 1836 in Vienna – September 28, 1921 in Vienna) was a famous Viennese and Parisian socialite of great charm and elegance. She was an important promoter of the work of the German composer Richard Wagner and the Czech composer Bedřich Smetana. In 1856, she married Prince Richard von Metternich, a son of chancellor Prince Klemens Wenzel von Metternich so they were a husband and a wife and an uncle and a niece simultaneously. They lived a happy conjugal life (despite his frequent love – affairs with actresses and opera prima donnas) They had three daughters.
She played an important role in the social and cultural life of Dresden and Paris, and after 1870 Vienna. She was a close friend and confidante of French Empress Eugénie, and Princess Pauline and her husband were prominent personalities at the court of Emperor Napoleon III She introduced fashion designer Charles Frederick Worth to the Empress and thus started his rise to fame.
Pauline was an ardent patron of music, and became a leader of fashionable society. Whether in Paris or Vienna, she set the latest social trends. She taught French and Czech aristocrats to skate and ladies to smoke cigars without fear of their reputations. She was acquainted with many composers and writers, including Richard Wagner, Franz Liszt, Charles Gounod and Camille Saint-Saëns, Prosper Mérimée and Alexandre Dumas), and corresponded with them. (wikipedia)