Grew up tough, spent longer in the Great War than was reasonable as reconnaissance, joined Steve Rogers, and seemed to die on the Eastern Front.  He was captured, brainwashed, repurposed as a Cheka assassin - first against the Polar Bear Expeditionary Force (y'know, where the US and their allies invaded the USSR), and then against the "enemies of the Communist International" by the Joint State Police Directorate (the OPGU, which was the predecessor to the KGB).

His "repurposing" involved a partial recreation of the super-soldier serum with "vril technology" and the installation of "the arm of St Ilia," a brass, amber, and ivory clockwork prosthetic preserved as a relic and also powered by vril.

He served on five continents, most of his missions completed with such finesse that no one knew he had ever been there.

In time, he was sent to the US for a mission, which went badly for his Soviet handlers and resulted in a partial return of his memory as well as breaking their mind control.

He is now trying to create a life in Depression-era New York.