He was a National Representative during the Hundred Days when Napoleon returned from Elba, a Deputy from 1815 to 1821, a peer of France and three times Minister of Finance.

[1] He did not approve of the French Revolution and remained at the bar, but took advantage of the opportunity to acquire national property in 1791.

During the Revolution and the Empire Roy was a leading provider of supplies to the Ministries of War and the Navy, which protected him from problems arising from his royalist sympathies.

[2] Roy's openly royalist leanings led to the Duke of Bouillon giving him enjoyment of the land of Navarre and the administration of its forests in 1798.

He acquired the greater part of the property of the Duke of Bouillon, who was having grave financial difficulties, in exchange for an annual payment of 300,000 francs.

The Navarre domains passed to the Empress Josephine, then to prince Eugène de Beauharnais and his son.

He was named Minister of State and member of the Privy Council, Commissioner of the Sinking Fund and of the Deposit and Consignment Office.

[1] When Jean-Baptiste de Martignac formed his ministry Roy was appointed Minister of Finance for a third time, holding office from 5 January 1828 to 7 August 1829.

King Charles X decided to form a strong reactionary cabinet under Jules de Polignac, and asked Roy to keep his portfolio.

He accepted the government of Louis Philippe I without hesitation and was often responsible for reports on taxes, the lottery and the budget.