Brief History

Rudi Gagarin has known Nick Fury and been on opposite sides of the former SHIELD director for probably 40 years. Gagarin's military career started in Stalingrad when, at only seven years old, Rudi carried ammo and water across battlefields to aid Russian troops (it is rumored that he was also involved in some killings and may have slit enemy soldiers throats despite his young age).

Rudi was one of, if not the first person recruited into the Russian Special Forces. With his skill and tactical brilliance he quickly climbed the chain of command and achieved the rank of Major by the age of twenty. As major he commanded forces several African states such as Libya and Angola. 
He left the Russian military in the early sixties to join Hydra. After his stent with Hydra he got involved in Vietnam, running sniper schools for the Vietcong and the North Vietnamese Army.

His skill and notariety gained him the attention of The United States Government, who promptly sent out a seal assasination team to dispose of him. The first team failed in their mission as did the three other seal assasination teams sent to eradicate him. In every attempt on his life Gagarin killed each and every member of the four seal team units single-handedly. In 1981 Gagarin went into the Afganistan mountains and learned the terrain better than the natives. He hunted and killed a confirmed two-hundred and sixty five Muhjahdeen troops before he dissapeared.