Upon his release, Dumouriez married his cousin, a certain "Mademoiselle de Broissy", but he proved a neglectful and unfaithful husband, and in 1789 the couple separated. Madame Dumouriez took refuge in a convent. In the meantime, Dumouriez had turned his attention to the internal state of his own country, and amongst the very numerous memoranda which he sent to the government was one on the defence of Normandy and its ports, which procured for him in 1778 the post of commandant of Cherbourg, which he administered with much success for ten years. He became a "maréchal de camp" in 1788, but his ambition was not satisfied.