On the assumption of the Imperial dignity by Napoleon, the Ottoman Porte, dazzled by the apparently irresistible splendour of his fate, sent an embassy to congratulate him; and in effect the ancient alliance between France and Turkey was re-established. Napoleon consequently had little difficulty in procuring from Constantinople a declaration of war against Russia, the great hereditary enemy of the Turk, at the time when he was about to encounter the armies of the Czar in Poland. The Dardanelles were shut against Russian vessels; and the English government, considering this as sufficient evidence that the Grand Seignior was attaching himself to the Antibritannic Confederacy, despatched a squadron of ships under Admiral Duckworth, in February, 1807, with orders to force the passage of the Dardanelles, present themselves before Constantinople, and demand from the Porte the custody _pro tempore_ of all her ships of war. The Turks negotiated for a week upon this proposal, but in the meantime increased and manned their fortifications, under the direction of French engineers, with such skill, that the English admiral began to be seriously alarmed for his own safety; and at length, on the 1st of March, effected his retreat through the Straits with considerable loss--this disgrace being the only result of his expedition. On the 20th of the same month (of March, 1807) another English expedition under General Fraser, having sailed from Sicily to Egypt, took possession of Alexandria. But every subsequent step they took proved unfortunate: after severe loss the English were compelled to enter into a convention with the Turks, and wholly evacuate Egypt on the 20th of September. In January, 1807, an English expedition landed near Montevideo, and carried that city by assault. Sir Home Popham, the admiral, was recalled, and tried by a court-martial, on the ground that he had undertaken this warfare without due authority; but he escaped with a reprimand, and new reinforcements were sent out, first under General Crawford, and secondly under General Whitelocke. The last-named officer invested Buenos Ayres, and commanded a general assault of that town on the 5th of July; on which occasion, notwithstanding the excellent behaviour of the soldiery, he was repulsed with a loss of 2000 killed, wounded, and prisoners; and reduced to such extremity, that he was soon afterwards glad to enter into a convention, and wholly withdraw the armament. The timid and incompetent Whitelocke was tried and cashiered. Some of these disasters were unknown at the time when Bennigsen demanded an armistice; but the general ill success of the British expeditions was notorious, and produced without doubt a very serious impression on the mind of Alexander.