From this time he was inseparably associated with Catherine in all important diplomatic affairs, though officially he was the subordinate of the vice-chancellor, Count
Ivan Osterman. He wrote all the most important despatches to the Russian ministers abroad, concluded and subscribed all treaties, and performed all the functions of a secretary of state. He identified himself entirely with Catherine's political ideas, even with that of re-establishing the
Greek empire under her grandson
Constantine. The empress, as usual, richly rewarded her comes with pensions and principalities. In 1786, he was promoted to the
Governing Senate, and it was through him that the empress communicated her will to that august state-decoration. In 1787 he accompanied Catherine on her triumphal progress through South Russia in the capacity of minister of foreign affairs. At
Kanev, he conducted the negotiations with the Polish king,
Stanislaus II, and at Novaya Kaidaniya he was in the empress's carriage when she received
Joseph II. The second
Turkish War (1787–1792) and the
Swedish war with
Gustavus III (1788–1790) heaped fresh burdens on his already heavily laden shoulders, and he suffered from the intrigues of his numerous jealous rivals, including the empress's latest favorite,
A. M. Mamonov. All his efforts were directed towards the conclusion of the two oppressive wars by an honorable peace. The
pause of Verela with Gustavus III (14 August 1790) was on the terms dictated by him. On the sudden death of
Potemkin, he was despatched to
Jassy to prevent the peace congress there from breaking up, and succeeded, in the face of all but insuperable difficulties, in concluding
a treaty exceedingly advantageous to Russia (9 January 1792). For this service he received the thanks of the empress, the
ribbon of St. Andrew, and 50,000 rubles. On his return from Jassy, however, he found his confidential post of
secretary of petitions occupied by the empress's last favorite,
Platon Zubov. He complained of this "diminution of his dignity" to the empress in a private memorial in the course of 1793. The empress reassured him by fresh honors and distinctions on the occasion of the solemn celebration of the peace of Jassy (2 September 1793), when she publicly presented him with a golden olive-branch encrusted with brilliants. Subsequently, Catherine reconciled him with Zubov, and he resumed the conduct of foreign affairs. He contributed more than any other man to bring about the downfall and the
third partition of Poland, for which he was magnificently recompensed. ==Grand Chancellor of the Russian Empire==