Sof'ja Sergeevna Trubeckaja

Sofia Sergeyevna Trubetskaya (; 8 August 1898) or Sophie Troubetskoy, Duchess of Morny (, ), later Sophie, Duchess of Sesto, was a Russian princess.

Life She was the daughter of Ekaterina Petrovna Mussina-Pushkina. Her father was either Ekaterina's husband the cavalry lieutenant Prince Sergey Vasilyevich Trubetskoy, making her their only child, or her lover Nicholas I of Russia of the House of Romanov. Her paternity was questioned right from her birth – shortly afterwards Sergey left for the Caucasus whilst Ekaterina went abroad, eventually settling in Paris with her daughter.

She met the Frenchman Charles de Morny, half-brother of Napoleon III, then special envoy to Russia, at the coronation of Alexander II. They married in St Petersburg on and moved back to France together. They had four children:

Charlotte (1858–1883), married José Osorio y Heredia, Count of Corzana, had a son; Auguste, Duke of Morny (1859–1920), married Carlotta Guzman y Ybarra, had two sons and one daughter; Serge (1861–1922), became an officer in the French army, died unmarried; Mathilde (1863–1944), married Jacques Godart, 6th Marquis de Belbeuf, had no children

They lived cosmopolitan lives in St Petersburg and Paris, with a love for exotic birds, monkeys and Japanese dogs. She organised social events, festivals and cultural gatherings to gain support and raise money for her husband's plan to restore the Spanish monarchy.

She was accepted into the Spanish aristocracy, becoming a dame of the Order of Queen Maria Luisa and introducing the tradition of the Christmas tree into Spain.

She died in Madrid in 1898.