Barclay led a large number of Russian troops approximately 100 km across the frozen Gulf of Bothnia in winter during a snowstorm.

After the Battle of Smolensk failed to halt the French and discontent among Russians continued to grow, Alexander I appointed Mikhail Kutuzov as Commander-in-Chief, though Barclay remained in charge of the 1st Army.

He became Commander-in-Chief in 1813 after the battle of Bautzen, replacing Wittgenstein (who had been appointed after Kutuzov's death early in 1813) and led the taking of Paris, for which he was made a Field Marshal.

Michael Andreas was born to Gotthard Barclay de Tolly (1734–1781) and his wife Margarethe Elisabeth von Smitten (1733-1771).

Their ancestor, Peter Barclay, belonged to the Towie or Tolly branch of the family and settled in Rostock in 1621; his son later moved to Riga in Livonia.

This was a common occurrence among the German Protestants, and it gave the young man an exposure to higher society unavailable in the Baltic provinces.

[7] The future field marshal started his active service in the Imperial Russian Army in 1776, and he would spend the rest of his life with the military.

Barclay commanded the right flank at the Battle of Borodino (7 September 1812) with great valour and presence of mind, and during the celebrated council at Fili advised Kutuzov to surrender unfortified Moscow to the enemy.

After Napoleon was driven from Russia, the eventual success of Barclay's tactics made him a romantic hero, misunderstood by his contemporaries and rejected by the court.

Barclay took part in the invasion of France in 1814 and commanded the taking of Paris, receiving the baton of a Field Marshal in reward.

As his health grew worse, he left the military and settled down in his Jõgeveste manor (German exonym: Beckhof, Polish: Tepelshof) (in what is now southern Estonia).

[12] Barclay de Tolly died at Insterburg (Chernyakhovsk), East Prussia, on 26 May 1818 (14 May, Old Style) on his way from his Livonian manor to Germany, where he wanted to renew his health.

His and his wife Helene Auguste Eleonore von Smitten's remains were embalmed and put into the mausoleum built to a design by Apollon Shchedrin and Vasily Demut-Malinovsky in 1832 in Jõgeveste.

After the extinction of the Barclay de Tolly princely line with his son Magnus on 29 October 1871 (17 October, Old Style), Alexander II allowed the field marshal's sister's grandson through female lineage, Alexander von Weymarn, to assume the title of Prince Barclay de Tolly-Weymarn on 12 June 1872 (31 May, Old Style).