Losing his father at a young age, he soon entered the French Navy, starting his service during the Seven Years' War, notably at the battle of Quiberon Bay.
He was visited at Brest by the future Tsar Nicholas I and his family and at Cherbourg on an inspection by Louis XVI of France.
He emigrated to Britain upon the French Revolution and - despite his lack of funds - raised a volunteer regiment known as the Régiment Hector ou Marine Royale.
[2] In the aftermath of the battle of Quiberon Bay seven French ships of the line and four frigates took advantage of the tide to reach the estuary of the river Vilaine, where they took refuge.
[2] For this the count of Hector was made a knight of the Order of Saint Louis in 1760 and promoted to capitaine de vaisseau on 15 January 1762.
[3] On 22 October 1780 the Naval Minister wrote to d'Hector, stating "The confidence which I know is your due will perhaps seem a burden in that I give you an excess of it, but, as it is only in the King's service, I do not think that you will find it indiscrete.
[4][5] The baronne d'Oberkirch visited Brest in June 1782 with the future Tsar Paul I and his wife Maria Feodorovna.
[4] On his departure from Cherbourg, Louis made d'Hector inspector of the main naval fortresses and charged him with submitting a plan for reforms to unify and coordinate the commands along the coast.
He moved to Koblenz in February 1791 and there was put in command of the Corps de la marine royale, solely made up of naval officers.
Constant Merland dans ses Biographie vendéennes (1884) dit de lui:[2] Naturellement obligeant, si son premier mouvement était un peu vif, il le corrigeait toujours par les bonnes grâces de ses manières, sachant parler et se taire à propos.
Pendant vingt-deux ans, si je passais par une porte cochère, j'étais toujours prêt à me casser la jambe.