It was the duty of the secret agents at the several capitals of Europe, who were always connected in some way with his Embassies, to keep his Majesty informed of all that was passing, and it became his custom to instruct them to bring about the realisation of his policy, regardless of the directions of his ministers. Louis XV. took an interest and a delight in foreign affairs, therefore to him the secret correspondence had its uses; otherwise—it was leading to destruction. One of the earliest and most remarkable of the King’s secret agents, for his employment as such dated from the year 1754 or 1755, was D’Eon de Beaumont, who, as a diplomatist, evinced spirit equal to that of Lord Whitworth under circumstances that have passed into history, and exhibited much of the bravery and daring of the famous Hugh Elliot, without, however, the similar advantage of being enabled to deal all his blows by the light of day, his training from youth having been in the direction rather of intrigue. Since no history of Louis XV. can have any pretensions to completeness if the name of D’Eon de Beaumont be excluded, it is not a little surprising that the individual acts, as well as the official services of so extraordinary a personage have never been brought together before the world. This blank the author endeavours to fill. In 1836, Gaillardet published a memoir of the Chevalier D’Eon, meretricious and spurious in its details, which speedily reached a second edition, and attained a popularity that caused it to be pirated and reproduced, very extensively, in ‘Un Hermaphrodite,’ Louis Jourdan indiscreetly lending his name for its authorship! Although Gaillardet announced that his book was produced out of material supplied by the D’Eon family at Tonnerre, its contents proved to be in great measure scandalous fabrications. Feeling himself, as he advanced in years, called upon to make some kind of reparation, this author gave, in 1866, a new edition under the title ‘Mémoires sur la Chevalière D’Eon. La Vérité sur les Mystères de sa Vie,’ in the preface to which, styled ‘Un Acte de Contrition, &c.,’ he candidly avows that his first edition was in great part a fiction. In this later edition Gaillardet reproduces, together with other interesting matter, numerous documents that are preserved at the Ministry for Foreign Affairs, where, by rare good fortune, he obtained permission to search the archives; and that so distinguished an academician as the Duke de Broglie (familiar to Englishmen as having been first minister in the Conservative days of the French Republic), as well as other well-known authors, should have availed themselves of this work, may be accepted as sufficient guarantee of its worth and reliability. As becomes a conscientious biographer, Gaillardet allows the documents he produces to speak for themselves, without himself undertaking to pass judgment on his subject; a safe course adopted in the following pages,