Princess Konstancja Poniatowska (1759–1830) was a Polish noblewoman from the House of Poniatowski. She was also the niece of King Stanisław August Poniatowski. Konstancja Poniatowska was born on March 2, 1759 in Warsaw, Poland. She was the only daughter of Kazimierz Poniatowski and his wife; Apolonia Ustrzycka. Konstancja had an elder brother, Stanisław Poniatowski (1754–1833). Konstancja later married Ludwik Skumin Tyszkiewicz on April 4, 1775. Konstancja was a close friend of the French Minister of Foreign Affairs, Charles Maurice de Talleyrand-Périgord. On March 26, 1779. Konstancja gave birth to Anna Tyszkiewicz. She was the only child of the couple.

Ancestry