At Jena, a year later, he had broken Prussia. He became master of the whole country. For the next seven years French garrisons held Berlin and all important Prussian places. The Czar was still in the field, but in June 1807 the Russian Army was defeated on the Eylau River. There followed the reconciliation of Napoleon and Alexander. On a raft upon the Niemen, with their armies gathered on either bank, the two Emperors met and embraced. Peace was made between them. And not only peace, but alliance. Alexander, estranged from England by the paltry support he had received, yielded himself to Napoleon's spell. The two potentates planned Europe according to their common interests. Alexander had his moments of revolt. When he reviewed the French Army and at Napoleon's side watched the Old Guard march past he was struck by the scars and wounds which many of these veterans bore. "And where are the soldiers who have given these wounds?" he exclaimed to Ney. "Sire, they are dead."

(http://www.autoadmit.com/thread.php?thread_id=3996546&forum_id=2...id.#36203949)

Many voices had warned Napoleon of the hardships and difficulties of campaigning in Russia. Nor did he disregard their advice. He had assembled what seemed for those days abundant transport and supply. It proved unequal to the event. In June 1812 he crossed the Niemen and headed straight for Moscow, some five hundred miles to the east. He was confronted by two main Russian armies totalling two hundred thousand men. His plan was to overwhelm them separately and snatch at the old Russian capital. He confidently expected that the Czar would then treat for peace. All the other sovereigns of Europe in similar circumstances had hastened to bow the knee. But Russia proved a different proposition. In this fateful month of June the Russian Ambassador in London made a startlingly accurate prophecy. It reflected the expectations of the Czar and his advisers. “We can win by persistent defence and retreat,” he wrote. “If the enemy begins to pursue us it is all up with him; for the farther he advances from his bases of supply into a trackless and foodless country, starved and encircled by an army of Cossacks, his position will become more and more dangerous. He will end by being decimated by the winter, which has always been our most faithful ally.” Defence, retreat, and winter, on these resources the Russian high command relied. Napoleon had studied the amazing Russian campaigns of the great Swede, King Charles XII. He thought he had profited by his reading. In the twentieth century another more ruthless dictator was to study Napoleon’s errors. He too thought he had marked the lesson. Russia undeceived them both.

Before Napoleon the Russian armies fell back, avoiding the traps he set for them and devastating the countryside through which the French had to pass. At Borodino, some sixty miles west of the capital, the Russians turned at bay. There in the bloodiest battle of the nineteenth century General Kutusov inflicted a terrible mauling on Napoleon. Both the armies engaged, each of about a hundred and twenty thousand men, lost a third of their strength. Kutusov withdrew once more, and Moscow fell to the French. But the Russians declined to sue for peace. As winter drew near it was forced on Napoleon’s mind that Moscow, burnt to a shell by accident or by design, was untenable by his starving troops. There was nothing for it but retreat through the gathering snows, the most celebrated and disastrous retreat in history. Winter now took its dreadful toll. Rearguard actions, however gallant, sapped the remaining French strength. Out of the huge Grand Army launched upon Russia only twenty thousand straggled back to Warsaw. Marshal Ney was said to have been the last Frenchman to quit Russian soil.

(http://www.autoadmit.com/thread.php?thread_id=3996546&forum_id=2...id.#36361103)

https://images.app.goo.gl/qaWBnbd9nXnn6q386

(http://www.autoadmit.com/thread.php?thread_id=3996546&forum_id=2...id.#45330036)

Bourbons, boasted that he would bring his former master

back to Paris in an iron cage. He found he could not resist

the Emperor’s call, he joined Napoleon. Other Marshals who

had turned their coats now turned them again. Within eighteen

days of his landing, Napoleon was installed in the capital.

(http://www.autoadmit.com/thread.php?thread_id=3996546&forum_id=2...id.#37419163)