Ancien Regime

Fleurieu was born in Lyon. He joined the Navy on 31 October 1755 at Toulon as a Garde-marine, aged just 13 and a half. He subsequently took part in the campaigns of the Seven Years' War— which ended in 1763— participating in the battles of Mahon, Lagos, and Les Sablettes and rising to brigadier in the gardes de la marine company, and then enseigne de vaisseau. In suggesting de Fleurieu's promotion to ensign, on 23 March 1762, the Minister wrote to the king:

he combines the wisest of conducts and greatest of dedications with extraordinary knowledge and the most favourable disposition to become a distinguished officer. His commanding officers hold him in the highest regard, and have put him forwards as a candidate for promotion, as to benefit the service and be an example to others.

On 1 July 1765 he was made Enseigne de port, and on 27 July he went to Paris to study horology with Ferdinand Berthoud.

He took part in a one-year sea campaign to test Berthoud's first marine chronometer, in an attempt to beat Britain in the race to find a reliable way to calculate longitude. The chronometers he thus refined with Ferdinand Berthoud for their later experiments were the object of major struggles with the king's horologer, Pierre Le Roy. Finally Claret de Fleurieu and Berthoud were entrusted with the task, setting out on the testing expedition from autumn 1768 to 11 October 1769 on the corvette Isis under Fleurieu's command. The chronometers almost invariably indicated the hour as accurately after the ship had left port, as if they were still on land. Knowing the actual local time at each present location by astronomy, they could easily determine the ship's exact position and longitude on a chart. The results of their observations was published in 1773 under the title Voyage fait par ordre du roi, pour éprouver les horloges marines ("Voyage made by order of the king, to test marine chronometers"). We can also cite among his major works le Neptune du Nord or l'Atlas du Cattegat et de la Baltique, an atlas of the Kattegat and the Baltic Sea that took him 25 years.

Made lieutenant de vaisseau on 1 October 1773, then deputy inspector of naval charts and plans, he also became deputy inspector of the naval academy on 15 May 1776. He was presented to the king and named capitaine de vaisseau on 5 December 1776 and soon afterwards director of ports and arsenals in January 1777, a post heading the fleet's organization of matériel, works and movements created specially for him by Louis XVI and one he held for 15 years. In it he directed nearly all planning for naval operations in the 1778-83 war against England as part of France's involvement in the American Revolutionary War, as well as all the French voyages of discovery such as that of La Pérouse.

French Revolution

The king made him Ministre de la Marine et des Colonies on 26 October 1790. He and the king wanted to separate the naval and colonial ministries, but the Assemblée nationale thought otherwise, and he resigned on 15 April 1791. Later that year he was made guardian of the Dauphin, later Louis XVII. He remained in the Tuileries on 10 August 1792, in support of Louis XVI right up until the critical point, but fortunately for him the revolutionaries did not discover this. In the midst of the Reign of Terror, in September 1793, Charles Pierre was arrested due to a letter of recommendation Louis XVI had sent to the Assemblée nationale, published in the Universal Monitor on 17 April 1791, in which he first demanded Charles' nomination as the Dauphin's governor. He remained imprisoned with his wife in the Madelonnettes for 14 months; they were finally released to find their homes, furniture, lands and resources dispersed and destroyed. A letter to the section des piques in the prison. discovered in Robespierre's house. speaks of a first arrest, which may suggest Charles was arrested several times and transferred from prison to prison. After the fall of Robespierre he was made a member of the Bureau des longitudes and of the Institut after M. de Bougainville's resignation in 1795. In 1797 (year V) he was elected deputy for the Seine in the Council of Ancients under the name Claret-Fleurieu. He remained so until the coup d'état of 18 Fructidor when he was excluded from the council. He was elected a member of the Conseil d'État on 24 December 1799.

First French Empire

On 30 September 1800, as Minister Plenipotentiary, he signed a treaty of friendship and commerce between France and the United States at Morfontaine, alongside Joseph Bonaparte. A member of the Council of State in 1800, he presided over its naval section and was interim Minister of the Navy several times during 1803 and 1804. He was named Quartermaster General of the emperor Napoleon's household and of the Imperial civil list on 10 July 1804.

On 24 July 1805 he was elected a member of the Sénat conservateur and made a Grand Officer of the Legion of Honor. On 1 August 1805, he was made Governor of the Tuileries and the Louvre, taking the oath before the Emperor on 8 September that year. On 2 February 1806 he was elected one of the seven senators who composed the Council of Administration within the Senate for that year. In 1808 he was made Councilor of State for life and an Imperial Count. On 7 September of that same year, Napoleon put him in charge of the investigation into the French defeat at the Battle of Trafalgar.

He died in Paris from a devastating cerebral hemorrhage, a few seconds after embracing his two daughters. Napoleon rewarded his services by giving him a state funeral and having his remains transferred to the Panthéon.