Prussian diplomat Jean-Pierre de Chambrier d'Oleyres was born on October 27, 1753 in Neuchâtel and died on December 30, 1822 in the same city.
In 1780, he received from the King of Prussia Frederick II the patent of chamberlain and was appointed minister plenipotentiary in Turin, where he remained until 1805. In 1782, his property was erected into a barony. He was Minister Plenipotentiary of Prussia in Switzerland from 1805 to 1814. In 1806, King Frédéric-Guillaume III instructed him to hand over the principality of Neuchâtel to General Nicolas-Charles Oudinot, Napoleon's commissioner, who then offered it to Marshal Berthier. In 1813-1814, after the invasion of Switzerland by the Allies, Frédéric-Guillaume commissioned him as negotiator for the resumption of Neuchâtel under Prussian sovereignty and appointed him governor and lieutenant general of the principality, a position he held until 1822 and to which he was the only Neuchâtel resident to have acceded. Promoted Minister of Prussia to the Federal Diet, he participated very actively in the negotiations which, on September 12, 1814, led to the admission of Neuchâtel as the twenty-first canton of the Confederation. Member from 1769 of the Société du Jardin, one of the initiators in 1791 of the Société d'emulation patriotique which he chaired from 1815 to 1822. Member of the academies of Turin (1774), Berlin (1792), he published several historical and political studies.