Amelot was dismissed in May 1743 and replaced in November 1744 by René D'Argenson, who served in the army with his brother, the Marquis d'Argens. In July 1745, Prince Charles landed in Scotland, launching the 1745 Jacobite rising and D'Argenson asked D’Éguilles to go there as an unofficial envoy; not being a professional diplomat made it easier to disown him if needed but he was hampered in his mission by the inability to speak English. He left Dunkirk on 26 September on board the French privateer "l'Ésperance", with two other ships carrying weapons and money, arriving in Edinburgh on 14 October. He claimed to simply be a gentleman 'driven by adventure,' but Charles introduced him as Ambassador, using him as proof of French support for the Rising.