Wolverine

WWII
Wolverine (James Howlett) was born in the 1880s. Much of Wolverine's early life is unknown, what is known is that he is a WWII Veteran. At some point he joined the Howling Commandos and served under Sergeant Jack Fury. During a fight with Hydra soldiers he was asked for recon by Jack Fury. He replied "I'm working on it bub!". He put up a good long fight and was aided by Captain America. At some point after the war the Howling Commandos disbanded and the members went their separate ways.

Weapon X
Much later, Howlett joined Weapon X's black ops unit Team X and was codenamed "Weapon X". He worked closely with fellow agent Sabretooth, but they drifted apart when he fell in love with another agent, Raven Darkholme codename Mystique. He later had adamantium implants put on his bones and had adamantium claws surgically installed. It is unknown whether or not he had these changes installed willingly, but he objected when Mystique was forcibly subjected to experimentation by Dr. Cornelius. He stopped Dr. Cornelius from carrying out the experiment, but was confronted by his former partner Sabretooth. At one point, he was sent on a mission with his partner Sabretooth to kill Christopher Nord, whom Sabretooth described as a maverick. When Nord went out to his work shed, Weapon X saw that Nord had a daughter. He refused to orphan the girl. At some point, he was taken back to the Weapon X facility, presumably for reconditioning.

With the X-Men
Wolverine sought help from Professor X for his memory problem and agreed to stay at the Xavier Institute as a member of the X-Men.