 Kasimierz had a son, Stanisław Poniatowski 1754–1833, whose son, Giuseppe Luci (1816–1873), by his mistress Cassandra Luci, was recognized and ennobled in the Austrian Empire on 19 November 1850 as Joseph Michel, Prince Poniatowski, a name and title recognised by Napoleon III when Poniatowski was naturalised in France and became a senator there, both in 1854.Two years later in Paris, Joseph's son, Prince Stanislas Poniatowski (1835–1908), married Louise Le Hon, generally reputed to be the daughter of Countess Le Hon ("née" Fanny Mosselman) by Charles, Duke de Morny, the illegitimate son of Charles Joseph, comte de Flahaut by Hortense de Beauharnais, sometime Queen consort of Holland as well as the adopted and step-daughter of Napoleon I; thus Louise Le Hon (as a granddaughter of Napoleon III's uterine half-brother) was a niece of the Emperor of France at the time of her marriage to Poniatowski, who was appointed the emperor's aide-de-camp.Their son, André Poniatowski (1864–1954) wed Stockton flour mill heiress Elizabeth Sperry in 1894.