Decrès was born in Châteauvillain, Haute-Marne on 18 June 1761 and joined the Navy at the age of 18, in the squadron of Admiral De Grasse.

While he was a member of the crew of the Richmond, during the Battle of the Saintes on 12 April 1782, he went in a boat under fire from British ships to attach a tow cable to the Glorieux, which had been dismasted, to bring it out of the danger in which it was placed.

He was restored to his rank of capitaine de vaisseau in June 1795, and promoted to command of the 80-gun ship Formidable in October 1795.

Attacked by three British ships as he was trying to break the blockade of Malta on 30 March 1800, with 200 sick and 1000 soldiers aboard, he surrendered early next day with half of his crew killed or wounded.

During this period, he organised French efforts to re-establish slavery in France's colonies, and Decrès was strong expounder of proslavery thought.

[3][4] Upon Napoleon's return from Elba to France, Decrès briefly resumed his post as Minister of the Navy during the Hundred Days from 20 March to 22 June 1815, and from then until his successor was appointed on 7 July.