According to Władysław Konopczyński, his father was Franciszek de Paula, but his mother was Maria Karolina Radziwiłł, who was divorced at the time.

[1] It is likely that shortly after the death of his first wife, he entrusted his two children, Teodora and Józef, to the care of his cousin, Prince Aleksander Antoni Sułkowski, at his Viennese court.

[1] Teodora was placed in a boarding school in Warsaw, while Józef Sułkowski was sent to Rydzyna under the care of the Piarist Ildefons Zawadzki and Michał Sokolnicki.

From 1779, Józef traveled across Europe with Prince August, visiting Paris, Naples, the Netherlands, Great Britain, Spain, and Portugal.

During his stay in Saint Petersburg, he received the rank of officer aspirant in the Horse Guards Regiment from Empress Catherine II.

Sułkowski witnessed the adoption of the Constitution of May 3rd, which he already regarded as not radical enough, a view he expressed in his work Le dernier Cri d'un citoyen polonais.

After the king joined the Targowica Confederation and Antoni Sułkowski was appointed Grand Chancellor of the Crown, he decided, influenced by his friend Piotr Maleszewski, to leave for France, where he arrived at the beginning of 1793.

Sułkowski planned to make a name for himself in the French service in order to better assist in the fight for Polish independence.

[1] On 28 June he arrived in Livorno, Bonaparte assigning him to General André Masséna's division where he was given the post of aide-de-camp with the rank of captain.

On hearing of his death Bonaparte showed remorse and, asked why he did not honour him more when he was alive, replied "On first meeting him, I saw in him a commander in chief".

Shortly before his death, he had married one of the daughters of Venture de Paradis, an old military interpreter and scientist on the Egyptian expedition.