The Sinclair family were of the Swedish descent that left the Great Britain after the Glorious Revolution of 1688 and pledged allegiance to Alexis of Russia.

Volodymyr studied at the Nepliuyevsky cadet corps and later at Mikhailov Artillery Academy in Orenburg, Russia.

During the Hetmanate and the Directorate he continued to serve in the General Staff, playing an important role in capture of Kiev from Bolsheviks in 1919.

After the military defeat of the Army of UNR retired and settled in Eastern Poland, participated in the life of the local Ukrainian community.

At the end of Second World War with the advance of the Red Army was arrested by NKVD and interned to Kiev.