being called to the bar of the parliament of Paris, he wrote several political pamphlets, which gained him the acquaintance of the Prince de Conti, then head of Louis XV.’s secret diplomatic cabinet. The prince proposed to the king that D’Eon should accompany to Russia in the capacity of secretary. Chevalier Douglas, who was sent to Petersburg in 1757 to effect a reconciliation between the French and Prussian courts. This was a difficult task, owing to the animosity Count Bestucheff, the High Chancellor of Prussia, had vowed against France. The secret envoys contrived to form an understanding with the Vice-Chancellor, Count Woronzoff, and an intimate correspondence was set on foot between Louis XV. and the Empress Elizabeth, the letters passing through the hands of Woronzoff and D’Eon. On November 5, 1757, the Empress of Russia acceded to the convention concluded on March 21 of the same year between France, Austria, and Sweden, with reference to the exercise of the guarantees of the peace of Westphalia, in so far as they related to Germany. She acceded to it as a principal party, that is to say, bound herself by the same engagements as the other contracting parties. The accession of Russia was the more important, because that power had just been on the point of concluding an alliance with the courts of London and Berlin. D’Eon, who was selected to convey these happy tidings to Versailles, received from Louis XV. his portrait on a valuable snuff-box, which contained in addition an order on the royal treasury, and a commission as Lieutenant of Dragoons. He started again immediately for St. Petersburg, where, in the interim, the Marquis d’Hôpital had succeeded Chevalier Douglas. Both gentlemen concerted with the ambassador of the Empress of Austria the means they should employ to disgrace Count Bestucheff, and they were perfectly successful. Bestucheff was arrested by the orders of Elizabeth, while presiding at a council in the palace; all his papers were examined, and in his cabinet a memorandum was found of the suspicious persons he proposed to get rid of, among them being Douglas and d’Eon. After this operation, General Apraxin, although commanding the army, was recalled; General Tottleben shared the same fate, and the troops, being placed under other leaders, gained several victories over the King of Prussia. D’Eon, one of the most active agents in this revolution, returned to France in 1758, and in 1761 took part in the campaign of Germany as captain of dragoons, and aide-de camp to Maréchal de Broglie. At Ultrop he was severely wounded in the head and hip, while at Osterwyk, he charged with such impetuosity a Prussian battalion, consisting of 800 men, that he compelled it to lay down its arms.
On the re-establishment of peace, D’Eon accompanied the Duc de Nivernois to London, as Secretary to the Embassy. He continued from that capital his secret correspondence with the king’s privy council, and was the soul of the Embassy, whose nominal chief, as Walpole tells us, displayed such exaggerated confidence and friendship for him, that it trenched on the ridiculous. M. de Nivernois, having taken the first opportunity to return to France, D’Eon continued to direct affairs at London under the title of resident, and as the arrival of the new Envoy was delayed, he was eventually nominated Minister-Plenipotentiary. He had already rendered himself so agreeable to the Court of St. James, that George III. had selected him, though contrary to usage, to bear to France the ratification of the treaty, and on this occasion Louis XV. presented him with the cross of St. Louis. So much good fortune appears, however, to have turned the head of the young Secretary to the Embassy, whose merit and literary capacity Walpole himself condescends to recognise: from this moment he forgot the modesty he had always displayed in his language and conduct. Moreover, some reverses happened to him, when the successor-elect of the Duc de Nivernois arrived in London. This gentleman was the Count de Guerchy, who had distinguished himself in the Flanders campaign, under Maréchal de Saxe, and in the lately terminated war, contributed no little to the victory of Hastembeck. Walpole describes him as an agreeable soldier, possessing no extraordinary capacity, but great knowledge of the world, indefatigable zeal and polished manners, but unfortunately under the supreme control of his wife, a very ugly and insignificant person, although extremely sensible and most faithful to her husband—possibly pour cause. Guerchy was not at all disposed to grant D’Eon that influence he had enjoyed under his predecessor, and from the first moment of his arrival made the secretary feel his dependent position. D’Eon had not received his salary regularly, while the funds intended for his superiors had arrived most punctually. Hence, in order to meet the expenses entailed on him by his title of Minister-Plenipotentiary, he had spent in three months, and without any authority, 50,000 francs of the money intended to provide for the establishment of the Count de Guerchy, who made some insulting remarks to him on the subject. He also annoyed him about pettifogging trifles,—as for instance the subscription to sundry newspapers. D’Eon asserted, moreover, that, as he had held the title of Minister-Plenipotentiary, he had a right to retain it, even after de Guerchy had handed in his credentials, and alleged with some show of reason, that he could not appear as a simple secretary at a court to which he had been accredited as minister.
These squabbles appear really to have disturbed this ambitious man’s senses. About this time an adventurer, of the name of Treyssac de Vergy, arrived in London, and D’Eon took it into his head that he had been sent expressly to assassinate him. When dining with Lord Halifax, he misunderstood the meaning of an expression made by the host, owing to his imperfect knowledge of English. He imagined that Lord Halifax threatened to break the peace of which he, D’Eon, had carried the ratifications to Versailles, and rushed with such fury on the ambassador, that it was found necessary to call in a magistrate, who arrested D’Eon, while Treyssac de Vergy obtained a warrant against him for a breach of the peace. The French court recalled D’Eon, who refused to return to Paris, and the Versailles cabinet was