Napoleon received no answer to his message. The allied princes had sworn to each other to entertain no treaty while one French soldier remained on the eastern side of the Rhine. He therefore prepared for the difficult task of retreating with 100,000 men, through a crowded town, in presence of an enemy already twice as numerous, and in hourly expectation of being joined by a third great and victorious army. During the 17th the battle was not renewed except by a distant and partial cannonade. The allies were determined to have the support of Bernadotte in the decisive contest.
On the morning of the 18th the battle began again about 8 o'clock and continued until nightfall without intermission. Never was Napoleon's generalship or the gallantry of his troops more thoroughly tested than on this terrible day. He again commanded on the south and again, in spite of the vast superiority of the enemy's numbers, the French maintained their ground to the end. On the north the arrival of Bernadotte enabled Blucher to push his advantages with irresistible effect; and the situation of Marmont and Ney was further perplexed by the shameful defection of 12,000 Saxons who went over with all their artillery to the enemy in the very midst of the battle. These Saxons, forming nearly a third of the left, ran over to the Russians, entered their ranks, and at Bernadotte's request discharged their artillery on the French, their fellow-soldiers, whom they had just abandoned!
The loss on either side had been very great. Napoleon's army consisted chiefly of very young men, many were merely boys, yet they fought as bravely as the Guard. The failure of the Emperor was partly occasioned by a want of ammunition; as in the course of five days, having fired more than two hundred and fifty thousand shots, his troops had not sufficient to continue the firing two hours longer. As the nearest reserves were at Magdeburg and Erfurt, Napoleon determined to march for the latter place. He gave orders at midnight for the commencement of the inevitable retreat, and while the darkness lasted, the troops continued to file through the town, and across the two bridges, over the Pleisse, beyond its walls. One of these bridges was a temporary fabric and broke down ere daylight came to show the enemy the movement of the retreating French.
The confusion necessarily accompanying the march of a whole army, through narrow streets, and upon a single bridge, was fearful. The allies stormed at the gates on either side, and, but for the heroism of Macdonald and Poniatowski, to whom Napoleon intrusted the defense of the suburbs, it is doubted whether he himself could have escaped in safety. At 9 in the morning of the 19th Napoleon bade farewell to the King of Saxony who had remained all the while in the heart of his ancient city. The King was left to make whatever terms he could with the Allied Sovereigns.
The battle was now raging all round the walls and at 11 o'clock the allies had gathered close to the bridge. The officer to whom Napoleon had committed the task of blowing up the structure, when the advance of the enemy should render this necessary, set fire to the train much too soon. The crowd of men, urging each other on to a point of safety could not at once be stopped and soldiers, horses and cannon, rolled headlong into the deep, but narrow river. Marshal Macdonald swam the stream in safety, but the gallant Poniatowski, who defended the suburbs inch by inch, and had been twice wounded ere he plunged his horse into the current, sank to rise no more. This order was given to Poniatowski by the Emperor himself: "Prince" said Napoleon to him, "you will defend the southern faubourg." "Sire" he replied, "I have but few people." "Ah! well! you will defend yourself with what you have." "Ah! Sire, we will maintain it! We are always ready to perish for your Majesty." The illustrious, unfortunate Pole kept his word; he was never again to behold the Emperor. Later Napoleon said of him: "Poniatowski was a noble man, honorable and brave. Had I succeeded in Russia, I intended to make him king of Poland."
The body of the Prince was found on the fifth day by a fisherman. He had on his gala uniform, the epaulets of which were studded with diamonds, and upon his fingers were several rings covered with brilliants, while his pockets contained snuff-boxes of considerable value, and other trinkets. Many of these were eagerly purchased by Polish officers who had been made prisoners. Twenty-five thousand Frenchmen, the means of escape being entirely cut off, now laid down their arms within the city with more than two hundred pieces of cannon. In killed, wounded and prisoners, Napoleon lost at Leipsic at least 50,000 men.
"This defeat at Leipsic" says St. Amand, "was for Napoleon a combination of grief and surprise. Of all the battles he had fought, this was the first that he had lost. Up to that time he could boast that if he had been conquered by the elements he had never been conquered by man; and now he was to know for himself the sufferings he had inflicted on others. He was to learn by personal experience the bitterness of defeat, the anguish of retreat, the desperation of useless bloodshed. War, which up to this time had been a source of gratification to his unparalleled pride, now showed to him its horrors, with its humiliations and inexpressible anguish. The hour had struck when he could make tardy reflections on the emptiness of genius and glory on the intoxication of pride that had turned his head."
The retreat of the French through Saxony was a sad ending to the auspicious beginning which the Emperor had opened the campaign with. Napoleon conducted himself as became a great mind amidst great misfortunes; he appeared at all times calm and self-possessed, receiving every day that he advanced new tidings of evil, for the peasantry was hostile, supplies scarce, and added to this was the persevering pursuit of the Cossacks who attacked at every opportunity.
The Emperor halted for two days at Erfurt, where extensive magazines had been established, employing all his energies in the restoring of discipline. He resumed his march on the 25th of October, 1813, towards the Rhine. The Austro-Bavarians hastened to meet him and had taken up a position amidst the woods near Hanau before the Emperor reached the Mayne. He came up with them on the morning of the 30th, and his troops charged on the instant with the fury of desperation. Napoleon cut his way through ere nightfall, and Marmont, with the rear, had equal success on the 31st. In these actions the French lost 6,000 men but the enemy had 10,000 killed or wounded, and lost 4,000 prisoners.