evidence: Meanwhile, in the terrible weather and mud which hampered the troops from 18th-23rd September, Napoleon turned his attention to Russian manoeuvres, hoping to crush any resistance. Cossack bands, however, continued to thwart French attempts at control led by Murat. By the 26th September, Napoleon had discovered that Kutuzov's main forces were on the main Kaluga road. Over the end of September and the beginning of October, the Russian Army slowly retreated to Tarutino, where it took up a defensive position on 3rd October after clashes with Murat's troops. [...] Upon seeing the conditions at Vilna, several days after the Emperor's departure, Murat (who had been left in charge of the Grande Armée) decided to abandon Napoleon's plan and evacuate the town. On the 12th December, Kutuzov made his triumphant entrance into Vilna. And the day after, what was left of the Grande Armée limped back across the Niemen.