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Princess Izabela Elżbieta Czartoryska (née Countess Morsztyn) (1671–1756) was a Polish noble lady.
She married Kazimierz Czartoryski in 1693. Along with her husband she supported Prince of Conti as a candidate to the Polish throne. In 1736 in Warsaw, she established the first political salon, where politicians met and the Familia party conferred. Women played a significant role in those meetings.
One of her daughters, Konstancja (1700–1759, wed Stanisław Poniatowski, and was the mother of Stanisław August Poniatowski, king of Poland. She is an ancestor of Mathilde d'Udekem d'Acoz, Queen (Consort) of the Belgians. Izabela Elżbieta Morsztynand Prince Kazimierz Czartoryski's great-granddaughter Zofia Czartoryska and her husband Stanisław Kostka Zamoyski are Prince Leon Sapieha-Kodenski's parents-in-law. Prince Leon's great-great-granddaughter, Princess Zofia Sapieha-Kodenska, is Queen Mathilde's maternal grandmother, who died in a car accident with the princess's sister, Marie-Alix d'Udekem d'Acoz. They are 10th-generation ancestors to Queen Mathilde.