== Invasão napoleónica ==
During Napoleon's Invasion of Russia in 1812 Barclay assumed the supreme command of the 1st Army of the West, the largest of the Russian armies facing Napoleon. He proposed the now famous [[scorched earth]] tactic of drawing the enemy deep into one's own territory and retreated to the village of [[Tsaryovo-Zaimishche]] entre [[Moscovo]] e [[Smolensk]].
== Campanhas no estrangeiro ==
Barclay was re-employed in the field and took part in the campaign in [[Alemanha]]. After Kutuzov's death, he once again became commander-in-chief of the Russian forces at the [[Battle of Bautzen]] ([[21 de maio]] de []), and in this capacity serviu na [[Batalha de Dresden|Dresden]] (26 - [[27 de agosto]] []), [[Batalha de Kulm|Kulm]] (29 - [[30 agosto]] de []) e [[Batalha de Leipzig|Leipzig]] (16 - [[19 de outubro]] de []). In the latter battle he commanded a central part of the Allied forces so effectively that the tsar bestowed upon him the title of [[count]].