Mikhail Barclay de Tolly was born on December 24, 1761, in the estate of Pamushise, located in the Livonian province. He was the grandson of the mayor of Riga and the son of an officer in the Russian army, coming from a Scottish family that settled in the Baltic in the 17th century.

In 1776, Barclay entered military service. During the storming of Ochakov on December 17, 1788, he showed courage and composure, for which he was promoted to second major. He then participated in the Russo-Swedish War of 1788-1790 and commanded a battalion of the Petersburg Grenadier Regiment in the war with Poland in 1792 and 1794. For the capture of Vilno, now Vilnius, he was awarded the Order of Saint George of the 2nd class and received a promotion. In January 1807, at the Battle of Preussisch-Eylau, Barclay was severely wounded in his right arm and was treated in Memel, where he was visited by Alexander I. From that time, he enjoyed the personal favor of the emperor. In 1809, Barclay became a general of infantry, commander of the Russian troops in Finland, and governor-general of that province, and in 1810 he was appointed Minister of War. From March 12, 1812, he commanded the 1st Western Army. The retreat from the borders at the beginning of the Patriotic War of 1812 was explained by Barclay as a necessity to preserve the army to tire and hold back the enemy. After the surrender of Smolensk, he was accused of cowardice and treason, and the troops stopped greeting him with cries of 'hurrah.' On August 17, a new commander-in-chief, Mikhail Kutuzov, arrived in the army to replace Barclay and stop the enemy. On the day of the Borodino battle, August 26, 1812, Barclay, according to his own words, sought death but did not find it. Five horses were killed under him, and his heroism was noted with the Order of Saint George of the 2nd class. 'Providence spared the life that burdens me,' he wrote to Alexander I after the battle. Illness and a sense of uselessness forced him to leave the army and the ministerial post. In Kaluga, stones were thrown at his carriage, and people shouted, 'Here comes the traitor.' However, Alexander I continued to trust Barclay and awaited a suitable opportunity to return him to the army. On February 16, 1813, Barclay replaced Admiral Pavel Chichagov as commander of the 3rd Army and successfully besieged the fortress of Thorn, defeating a French division at Königswarte. At the Battle of Bautzen on May 8 and 9, 1813, he prevented Marshal Michel Ney from outflanking the right wing of the allies. In May 1813, Alexander I granted Count Peter Wittgenstein's request to appoint Barclay to his position. For his participation in the Battle of Nations near Leipzig in October 1813, Barclay was elevated to the rank of count. By the end of the war, he received numerous awards: the Prussian ribbon of the Black Eagle, a sword with diamonds and laurels, the rank of field marshal for the capture of Paris, and the position of commander-in-chief of the army. However, by early 1818, his health deteriorated, and he requested the emperor's permission to go for treatment in Germany. Barclay died on May 14, 1818, on the way, at the estate of Shtilitzen near Insterburg.