Breteuil was born in 1730 at the chateau of Azay-le-Ferron (Indre) into a well-connected aristocratic family: one of his relations was confessor to the king's cousin and another was the famed mathematician and linguist Émilie, marquise du Châtelet-Laumont. He received an excellent education in Paris and later joined the army, where he fought in the Seven Years' War. In 1758 he left the army and joined the French Foreign Ministry. He was quickly appointed French ambassador to the elector of Cologne, where he proved to have valuable diplomatic skills. Two years later he was sent to St Petersburg as the French ambassador to Imperial Russia, where he arranged to be temporarily absent from his post at the time of the palace revolution by which Catherine II was placed on the throne. In 1769 he w