At the close of May, the Sultan Selim was violently deposed by the Janissaries who clamoured for more vigorous measures against the Russians.

Never did news come more opportunely for Napoleon than this, which reached him at Tilsit on, or before, June the 24th.

He is said to have exclaimed to the Czar with a flash of dramatic fatalism: "It is a decree of Providence which tells me that the Turkish Empire can no longer exist."[146] Certain it is that the most potent spell exerted by the great conqueror over his rival was a guarded invitation to share in some future partition of the Turkish Empire.

That scheme had fascinated Napoleon ever since the year 1797, when he gazed on the Adriatic.
Though laid aside for a time in 1806, when he roused the Turks against Russia, it was never lost sight of; and now, on the basis of a common hatred of England and a common desire to secure the spoils of the Ottoman Power, the stately fabric of the Franco-Russian alliance was reared.
On his side, Alexander required some assurance that Poland should not be reconstituted in its integrity--a change that would tear from Russia the huge districts stretching almost up to Riga, Smolensk, and Kiev, which were still Polish in sympathy.

Here Napoleon reassured him, at least in part.