His orders and the despatch conveying Napoleon's instructions fell into the hands of the Cossacks, and just in time Bennigsen's eyes were opened.
The very day that Napoleon issued the order to cross the Niemen, and his vanguard, driving off the Cossacks, crossed the Russian frontier, Alexander spent the evening at the entertainment given by his aides-de- camp at Bennigsen's country house.
This letter had not yet been presented to the Emperor when Barclay, one day at dinner, informed Bolkonski that the sovereign wished to see him personally, to question him about Turkey, and that Prince Andrew was to present himself at Bennigsen's quarters at six that evening.
This room had probably been a music room; there was still an organ in it on which some rugs were piled, and in one corner stood the folding bedstead of Bennigsen's adjutant.
"Russia's ancient and sacred capital!" he suddenly said, repeating Bennigsen's words in an angry voice and thereby drawing attention to the false note in them.
Bennigsen's note and the Cossack's information that the left flank of the French was unguarded were merely final indications that it was necessary to order an attack, and it was fixed for the fifth of October.
But after Bennigsen's departure, the Grand Duke Tsarevich Constantine Pavlovich joined the army.