Philippe-Louis-Marc-Antoine, comte de Noailles, prince-duc de Poix, and duc de Mouchy (21 December 1752–15 February 1819), was the son of Philippe de Noailles and grandson of Adrien-Maurice, 3rd duc de Noailles. He held the courtesy title of prince de Poix as a child.
In 1789 he was elected to the Estates-General by the nobility of Amiens and Ham, but was compelled to resign in consequence of a duel with the commander of the National Guard at Versailles. He left the country for some time, but returned to France and took part in the revolution of 10 August 1792. He was, however, forced to quit the country once more to evade the fate of his father and mother, guillotined in 1794. On his father's death, he acceded to the titles of comte de Noailles and duc de Poix à brevêt and the Spanish title duc de Mouchy.
Returning to France in 1800, he lived quietly at his residence at Mouchy (Oise) during the Empire. At the Restoration he again came into favor and in 1817 was created duc de Mouchy as a French title, thus becoming a peer of France.
Note that the 1911 Britannica gives Noailles's dates as 21 November 1752–17 February 1819, but several other sources agree on the dates given above.
