Howlett's past is mostly unknown, but during World War II he participated in military airdrops with Captain America. Decades later, he was abducted and experimented upon by a covert government unit, who bonded unbreakable adamantium to his skeleton. Initially designated Weapon X (later the name of the entire unit), Howlett was renamed both "Logan" and "Wolverine." Weapon X held him for at least a decade. Supposedly programmed to kill any human he saw, he proved his humanity was intact by saving Nick Fury's life in the Middle East. He grew to hate his captors and also his fellow prisoner, Sabretooth.
Fury eventually helped him escape, and Wolverine became a mercenary, frequently working for Magneto's Brotherhood of Mutants. He was constantly pursued by Weapon X, on one occasion evading them with the aid of the young adventurer Spider-Man. A year and a half after his escape, Wolverine was assigned by Magneto to assassinate Charles Xavier, leader of the X-Men. Successfully infiltrating the X-Men, Wolverine delayed his mission in order to romance Marvel Girl, but in the succeeding weeks he embraced Xavier's cause and turned on Magneto, fighting the Brotherhood alongside the X-Men. Soon afterward, Weapon X captured and enslaved most of the X-Men; Wolverine escaped, informed Nick Fury of the abductions, and then allowed himself to be captured in order to lead rescuers to Weapon X's secret base. While Wolverine was drawn into a grudge match with Sabretooth, the Brotherhood of Mutants raided the base, and Fury arrived to kill Wraith and guarantee the X-Men's freedom.
Wolverine remained jealous of Marvel Girl's boyfriend Cyclops, and when they investigated Magneto's abandoned Savage Land lair together, Wolverine left Cyclops to die. Wolverine helped the other X-Men battle Magneto and the Ultimates, but as the multi-front conflict reached its conclusion, Cyclops returned, exposing Wolverine's misconduct and kicking him off the team. Retreating into isolation, Wolverine was surprised when Cyclops, feeling Wolverine's rehabilitation outweighed their feud, invited him back and informed him S.H.I.E.L.D. had discovered evidence of his earlier life: a wedding ring.
Troubled by the revelation, Wolverine departed again, but was targeted by Weapon X renegades whom he defeated alongside Spider-Man and Daredevil. Wolverine has gradually regained the X-Men's trust, and been startled by a growing attraction between him and Storm.
Recently, Wolverine was killed by Magneto.