He was the son of Louis-Gabriel de Gueulluy, 1st Marquess of Rumigny (1761-1835), created Marquess by Louis XVIII, and Marie-Julie Hatte. His brother was Marie-Théodore Gueilly, vicomte de Rumigny a famous French general, and Aide-de-camp of king Louis Philippe I and his sister was married to viscount Pierre Charles Dejean.
In 1805 he enterred the French Service of foreign diplomacy and became a close confidant of the King. In 1839 he was ambassador in Madrid, and was remarked to be an excellent diplomate. He was Ambassador of the French king in Brussels and succeeded Louis Sérurier. Leopold I, King of the Belgians was son-in law of the French king. He did retire after the French revolution of 1848 in Brussels, where he died at high age.
