The man called Logan had already lived a long and violent life when he was kidnapped from his black ops team by a secret government program called Weapon X. In a high-tech lab deep in the Canadian Rockies, scientists bonded the unbreakable metal adamantium to Logan's bones, relying on his mutant healing factor to keep the experiment from killing him.
But Logan escaped the Weapon X program, and before too long drew the attention of Professor Charles Xavier, who recruited him to the X-Men as Wolverine. Despite the objections of those who saw him as more trouble than he was worth, Xavier saw Logan's inner nobility.
Wolverine constantly fights to keep his savage berserker side in check, but no matter how hard he tries, it's usually just a matter of time before he pops his claws and goes to work.