He was the eldest of eight surviving children of Princess Konstancja Czartoryska and of Count Stanisław Poniatowski, Ciołek coat of arms, Castellan of Kraków.

He was a great-grandson of the poet, courtier and alleged traitor, Jan Andrzej Morsztyn and through his great-grandmother, Catherine Gordon, lady-in-waiting to Queen Marie Louise Gonzaga, he was related to the House of Stuart and thereby connected to the leading families of Scotland, Spain and France.

He was created Prince by his brother, King Stanisław II August Poniatowski on 4 December 1764.

After the First Partition of Poland (1772), he sold off his Podkomorzy title, played no further part in politics and joined the "high life".

[3] On 21 January 1751 he married Apolonia Ustrzycka (1736–1814), a daughter of Bazyli Ustrzycki, castellan of Przemyśl, and widow of Prince Antoni Lubomirski.