Smolensk, called from its site the Key of Russia, and designated, from its importance as a shrine, "The Sacred," was then a town of about thirteen thousand inhabitants. Around the inner city was a line of thick but dilapidated walls, and these were surrounded outside by densely built faubourgs. The first attempt of Ney to storm the walls failed, and a bombardment was ordered. By evening of the seventeenth the French army were all drawn up on the north bank between the city and the river; the Russians were opposite on the heights. During the night of the seventeenth the Russian army began to cross the Dnieper by the permanent bridge, which they held; a fresh garrison was thrown into Smolensk, and at four in the morning of the eighteenth the van began to retreat toward Moscow. Napoleon, foiled in his attempt to carry Smolensk by storm, had hoped that Barclay would offer battle under the walls of the town. He, therefore, waited until afternoon for the expected appearance of his foe, but in vain. Puzzled and uneasy, he then determined to force the fighting by a fresh assault. The suburbs were captured late in the evening, but the walls were impregnable. Barclay then set fire to the quarter opposite that attacked by the French, and in the resulting confusion safely drew out his garrison; the next morning saw his rear well beyond Napoleon's reach, with the bridges destroyed behind it. On the twenty-third he halted and drew up for battle behind the Uscha. [Illustration: Map of the Russian Campaign 1812.]