On returning to King Louis, at Ghent, he resumed his duties of Minister for the War Department; and assuredly his task was both a severe and a difficult one.
He had to arrange the disbanding of the Imperial and the re-organization of a Royal army; he had to examine and decide upon the various claims presented by hundreds of soldiers; he had to satisfy the demands of two thousand officers who adhered to the king, and to send them into the interior; he had to classify nine thousand officers of the disbanded army; to arrange for the pay of six thousand others who were re-formed—that is, continued on pay, but without being regimented; he had to examine six thousand claims for arrears of pay and pensions, claims that could admit of no delay, and which amounted to forty-six millions of francs; he had to organize the Royal Garde du Corp; to reconstitute the gendarmerie; to provide for the maintenance of the allied armies of occupation; and all this he had to do, amid obstacles, disorders, and complexities without example.
Such was the mighty mass of labour submitted to the care of Clarke; and of this herculean task he nobly and ably acquitted himself in less than two years.
All impartial writers unite in exculpating him from the angry and unjust accusation of peculating with the enormous sums which were required and absorbed by the re-organization of the French army. But he was severely handled by military men for instituting those tribunals styled Les Cours Prévotales.
In June, 1815, Clarke was with Louis XVIII. at Arnouville, and while there saved his friend, François Marquis de Lagrange, a lieutenant-general who in 1813 commanded the 3rd Regiment of Gardes d'Honneur, from great danger, if not from death. The marquis had been accused of offering his services to Napoleon, and hastily arrived at Arnouville with his son, on the 30th June. As he was about to wait upon Louis he was assailed by several soldiers, in whose hearts the love of Napoleon was strong. They called him a traitor, and tore away his sword, cross, and epaulettes. On becoming aware of these outrages, Clarke sent two influential officers to repress the tumult, and himself led the marquis to Louis XVIII., who appointed him captain of the Black Musketeers.
The zeal which Clarke now employed in the cause of the house of Bourbon was ultimately the means of his downfall. Louis XVIII., who each day conceded more and more to the enemies of his dynasty, after bestowing upon Clarke the bâton of a Marshal of France, displaced him from office, and appointed Gouvin St. Cyr in his room.
We know that after his dismissal all was changed in the department of the Minister of War.
The position in which Clarke found himself during the last years of his stirring, active, and useful life was very painful and humiliating, especially to one of so proud a spirit as his. Some of the more favoured personages who crowded the court of Louis XVIII., could not behold with a favourable eye this foreigner, who had been the War Minister of the great Napoleon, a confidant of his, and his co-operator in a thousand schemes of conquest; on the other hand, his old comrades of the Imperial army affected to see in Clarke a deserter, a transferer of his allegiance, and, indeed, all but a traitor. Those whose base extortions he had repressed in other times now joined their clamours against him, and the Royalists cared not to say a word in his defence.
Thus, at the end of his career, he was unjustly despised alike for his talents and virtues, as for his mistakes and weaknesses—for the good he had done as well as for evil. Clarke now found himself isolated and abandoned, and the conviction of this, together with the coldness with which he was treated, sank deeply into his proud and sensitive heart.