Prince Michael Andreas Barclay de Tolly (27 December [O.S. 16 December] 1761 26 May [O.S. 14 May] 1818), known in Russia as Mikhail Bogdanovich Barklay-de-Tolli. Michail Bogdanovi Barklaj-de-Tolli), was a Russian Field Marshal and Minister of War during Napoleon's invasion of Russia in 1812 and subsequent campaigns of the Russian army in Europe.