He was the chief plenipotentiary at the abortive congress of Durovicha, which met in 1664, to terminate the Russo-Polish War; and it was due in no small measure to his superior ability and great tenacity of purpose that Russia succeeded in concluding with Poland the advantageous truce of Andrussowo (Feb.
He was last employed in the negotiations for confirming the truce of Andrussowo (September 1669; March 1670).
In 1664 a peace congress was opened at Durovicha and the prospects of Poland seemed most brilliant; but at the very moment when she needed all her armed strength to sustain her diplomacy, the rebellion of one of her leading magnates, Prince Lubomirsky, involved her in a dangerous civil war, compelled her to reopen negotiations with the Muscovites, at Andrussowo, under far more unfavourable conditions, and after protracted negotiations practically to accept the Muscovite terms. By the truce of Andrussowo (Feb.
But for the terrible and persistent ill-luck of Poland it is doubtful whether the "truce" of Andrussowo would ever have been signed.
By the truce of Andrussowo (February 1, 1667) Vitebsk, Polotsk and Polish Livonia were restored to Poland, but the infinitely more important Smolensk and Kiev remained in the hands of the Muscovite together with the whole eastern bank of the Dnieper.