There was a time when Viggo Mortensen, known for his role as Aragorn in The Lord of the Rings trilogy, was courted by Fox to play X-Men's Wolverine, but he turned it down and has just shared why after over 20 years. Wolverine's role eventually fell to Hugh Jackman, who played the character for 17 years, and has mostly had his career defined by it. Meanwhile, Mortensen found himself replacing Stuart Townsend as Aragorn for one of the great trilogies of film history instead, as the two projects were put together around the same time.
Few Marvel characters are more iconic than Wolverine, and few actors are more tied to their characters than Hugh Jackman as Wolverine. Though he was lucky and talented enough to transcend the association and find roles to fill elsewhere in Hollywood during his tenure, Jackman effectively is Wolverine. Even Joe Russo doesn't think he should be replaced until he wears from fans' memory. It can be weird to think about how many actors were considered before Jackman, but Viggo Mortensen likely would've been a great choice. The problem for him, ironically, was the thought of being defined by the character.
Mortensen was recently interviewed on the Happy Sad Confused podcast, promoting his directorial debut Falling. He mentioned on the show that he was uncomfortable with the idea of playing Wolverine too much, and funnily enough that his son was unimpressed by Bryan Singer's depiction of the character.
The thing that bothered me at the time was just the commitment of endless movies of that same character over and over. I was nervous about that. And also there were some things, I mean they straightened most of them out, but I did take Henry to the meeting I had with the director as my sort of good luck charm and guide. In the back of my mind I was thinking he could learn something too, because I did let Henry read the script and he goes 'This is wrong, that’s not how it is.’
Mortensen and Jackman both have enjoyed successful careers despite the iconic roles they accepted in the early 90s. Both are still at least partially tied to their defining franchises, though Mortensen mostly just gets asked about LOTR things, but have been free to accept other roles and artistic ventures and be taken seriously in them. It's yet to be seen how the MCU will deal with Wolverine, but Disney's hold on their Marvel characters does seem to be even more intense than Fox.
MCU characters show up a lot. For example, compared to Jackman's seven appearances (one of which was a cameo) in seventeen years, Robert Downey Jr. has played Iron Man ten times in only thirteen years. That's quite a commitment. Mortensen's directorial debut, Falling, was, unfortunately, a bit of a mixed bag, but directing a feature is quite an accomplishment in itself. Ultimately, the X-Men/LOTR decision appears to have been a win-win for everyone involved.
Source: Happy Sad Confused Podcast