Princess Konstancja Czartoryska was a Polish-Lithuanian noblewoman and the mother of King Stanisław August Poniatowski. She played a political role as a driving force within the Familia.

Stanisław II August, known also by his regnal Latin name Stanislaus II Augustus, and as Stanisław August Poniatowski, was King of Poland and Grand Duke of Lithuania from 1764 to 1795, and the last monarch of the Polish–Lithuanian Commonwealth.