Billy Grey was born around 1971 in Acter, Alderney. He was introduced to violence and racism at a very young age, by watching news coverage of the Vietnam War and/or Chinese Cultural Revolution deaths when he was under 5 years old (as he arrogantly tells a Triad capo during Chinese Takeout). Around 1984, he was friends with Michael Klebitz when they were both 15, and Billy was introduced to his younger brother Johnny Klebitz, Johnny being 10 at the time. According to Michael, Billy "thought he was Jesus on an acid trip" and quickly became a bad influence on Johnny. Michael, in contrast, became a soldier in Iraq and an upstanding citizen, criticizing Billy's and Johnny's criminal biker lifestyle. In 1986, Billy was arrested for stealing a bike at age 15, which Johnny would soon imitate in 1991. Billy committed many other crimes and served up to two years in juvenile hall before he and Johnny both joined the Lost MC. He was arrested for murder in 1989 when he was 18, possibly alongside Brian Jeremy who was arrested for the same crime in the same year (whether or not, Brian would eventually be his most loyal follower in the Lost).
Billy worked his way up from a prospect to president of the chapter. Billy is shown to be a sadistic and violent leader and as president, he enacted the worst acts of violence to the Lost's ongoing rivals since 1982, The Angels of Death. During his presidency, he was to blame for an accident that handicapped fellow Lost member Angus Martin, and put their AOD rival Joe Jon's nephew in a coma. His drug problem severely worsened; He began using heroin. The mission This Shit's Cursed reveals that Billy used to take steroids.
At another point in time, Billy slept with Johnny's girlfriend Ashley Butler; although the social structure of any biker gang readily allows a member's girlfriend sleep around (referred to specifically as "property"), Johnny became understandably jealous but never outwardly criticized Billy for it. He supposedly ended his relationship with her because of her extreme drug habit.thumb|400px|right