During the latter part of the life of this King, the Marquis of Lucchesini was frequently of his literary and convivial parties; but he was neither his friend nor his favourite, but his listener.  It was first under Frederick William II. that he began his diplomatic career, with an appointment as Minister from Prussia to the late King of Poland.  His first act in this post was a treaty signed on the 29th of March, 1790, with the King and Republic of Poland, which changed an elective monarchy into an hereditary one; but, notwithstanding the Cabinet of Berlin had guaranteed this alteration, and the constitution decreed in consequence, in 1791, three years afterwards Russian and Prussian bayonets annihilated both, and selfishness banished faith.

In July, 1790, he assisted as a Prussian plenipotentiary at the conferences at Reichenback, together with the English and Dutch Ambassadors, having for object a pacification between Austria and Turkey.  In December of the same year he went with the same Ministers to the Congress at Sistova, where, in May, 1791, he signed the Treaty of Peace between the Grand Seignior and the Emperor of Germany.  In June, 1792, he was a second time sent as a Minister to Warsaw, where he remained until January, 1793, when he was promoted to the post of Ambassador at the Court of Vienna.  He continued, however, to reside with His Prussian Majesty during the greatest part of the campaign on the Rhine, and signed, on the 24th of June, 1793, in the camp before Mentz, an offensive and defensive alliance with your Court; an alliance which Prussian policy respected not above eighteen months.  In October, 1796, he requested his recall, but this his Sovereign refused, with the most gracious expressions; and he could not obtain it until March, 1797.  Some disapprobation of the new political plan introduced by Count von Haugwitz in the Cabinet at Berlin is supposed to have occasioned his determination to retire from public employment.  As he, however, continued to reside in the capital of Prussia, and, as many believed, secretly intrigued to appear again upon the scene, the nomination, in 1800, to his present important post was as much the consequence of his own desire as of the favour of his King.

The Marquis of Lucchesini lives here in great style at the beautiful Hotel de l’Infantado, where his lady’s routs, assemblies, and circles are the resort of our most fashionable gentry.  Madame da Lucchesini is more agreeable than handsome, more fit to shine at Berlin than at Paris; for though her manners are elegant, they want that ease, that finish which a German or Italian education cannot teach, nor a German or Italian society confer.  To judge from the number of her admirers, she seems to know that she is married to a philosopher.  Her husband was born at Lucca, in Italy, and is, therefore, at present a subject of Bonaparte’s brother-in-law, Prince Bacciochi, to whom, when His Serene Highness was a marker at a billiard-table, I have had the honour of giving many a shilling, as well as many a box on the ear.