Mikhail was born in Saint Petersburg on December 23, 1863, to Lieutenant-General Aleksei Mikhailovich Belyaev.

In late November 1893, he was appointed the senior adjutant of the 24th Infantry Division of the 1st Army Corps.

From mid August 1905 till the end of the war, he was the Chancery of the new commander-in-chief, the aged general Nikolai Linevich.

But later in early August 1916, he was relieved from his post and became a member in the Military Council and a representative of the Russian command at the Romanian Main Apartment.

And in early 1917, he replaced General Dmitry Shuvayev as Minister of War, becoming the last in the Russian Empire.

[2] After the revolutionaries captured Petrograd, General Belyaev was arrested and was put in custody in the Peter and Paul Fortress.

After his rearrest, he was questioned by the Extraordinary Investigative Commission of the Provisional Government, but they failed to accuse the general of any crimes.