In 1755 the Prince de Conti, to whose notice the Chevalier had been brought by the above books, asked the king (Louis XV) to send him to Russia on a secret mission with the Chevalier Douglas; and from that time till the king’s death in 1774 he was his trusted, loyal agent and correspondent. D’Eon’s special mission was to bring the courts of France and Russia closer than had been their wont, and also to obtain for the Prince de Conti, who was seeking the Dukedom of Finland and the Kingship of Poland, the favour of the Empress Elizabeth--a difficult task, which had already cost M. de Valcroissant a spell of imprisonment. In order to accomplish his mission, d’Eon disguised himself as a woman, and in this guise he was able to creep into the good graces of the Empress. He became her “reader” and was thus enabled to prepare her for the reception of the secret purposes of his king. In the following year he returned to France whence he was immediately sent again to St. Petersburg with the title of Secretary of Embassy. But this time he went in his man’s clothes and as the brother of the pretended female reader. By this time he had been made a lieutenant of dragoons. He came in spite of the Russian Chancellor Bestuchéf, who saw in the young soldier-diplomat “_un subject dangereux et capable de boulverser l’empire_.” This time his real mission was to destroy in the mind of the Empress faith in Bestuchéf, who was trying to hold the Russian army inactive and so deprive France of the advantages of the Treaty of Versailles. This he did so well that he was in a position to prove to the Empress that her chancellor had betrayed her interests. Bestuchéf was arrested and his post conferred on Count Woronzow, whose attitude was altogether favourable to France. The gratitude of King Louis was shewn by his making d’Eon a captain of dragoons and conferring on him a pension of 2400 livres; he was also made censor of history and literature. D’Eon threw himself with his accustomed zeal into the service of the army and distinguished himself by his courage in the battles of Hoecht; of Ultrop, where he was wounded; of Eimbech where he put the Scotch to flight; and of Osterkirk, where at the head of 80 dragoons and 20 hussars he overthrew a battalion of the enemy. No better conventional proof of the accepted idea of d’Eon’s military worthiness can be given than the frequency and importance of the occasions on which he was honoured by the carrying of despatches. He brought news of his successful negotiations for the peace of Versailles from Vienna in 1757. He was also sent with the Ratification of the Treaty. He carried the despatches of the great victory of the troops of Maria Theresa, forestalling the Austrian courier by a day and a half, although he had a broken leg.