Does anybody know any instances where the main character was recast?

This is obviously fuelled by Henry Cavill leaving Netflix's The Witcher, in which he played the Witcher, and the role being filled by Liam Hemsworth. This isn't about whether or not that's a good thing but it got me curious about recasting the main character. I feel like usually the main actor leaving means the thing doesn't go on. I couldn't think of an example and didn't find any online, either. All the lists I found listed (although major) side characters or ensemble cast members, like Dumbledore or Laurie Forman. So my question boils down to:In either movies or TV, has there ever been an instance of the singular main character being recast?Edit: To get in front of this: I don't mean actors changing during production, I mean actor A playing a role in a movie/episode/season and actor B reprising the role in a sequel/new season.And except James Bond via /r/movies https://ift.tt/BmXu6Ro