Sollogub was born into a noble family in the Minsk Governorate of the Russian Empire.

From September to December he was a staff officer for the Western Front army group under Alexander Miasnikian.

[1] Sollogub joined the Red Army in early 1918 and initially served as the first chief of staff of the Eastern Front from June to July.

[1] In May 1919 he was attached to the chief of staff of the Western Front before receiving command of the 16th Army during the Polish-Soviet War in August.

Under his command the army advanced westwards into Poland before being thrown back during the Battle of Warsaw.