It was a lightning in a bottle performance. One we will likely never see again. And all the more amazing since Williamson had a reputation for being mercurial and difficult and fairly disliked by many in the industry. But this performance dominated the film almost to its detriment since you could feel his absence when he wasnt around and I dont know about you all but every time I watch it and his entombment scene comes, I feel a real sense of disappointment knowing he will no longer be a part of the film in any real sense after that.
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Best Merlin no question. I also agree he is the best thing about the film.
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Without a doubt, no one even comes close.

When the script calls for him to deliver a 'comic relief line', he "out Pythons" the Pythons.
To me, his Merlin is one of the best performances ever filmed.

His performance has captivated me since I first saw the film back in the 80's. The whole film is fantastic - everything it should be.

They didn't always see eye to eye and Boorman was initially weary of him being cast. Also funny; the actress who plays Morgana was an ex-girlfriend of Williamson's and they didn't want to work together either and reportedly both almost quit the project after learning the other had been cast.
Uh, that would be Helen Mirren, a well established actress.
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And what's funny is director John Boorman and Williamson are/were well known to be "frenemies". They didn't always see eye to eye and Boorman was initially weary of him being cast. Also funny; the actress who plays Morgana was an ex-girlfriend of Williamson's and they didn't want to work together either and reportedly both almost quit the project after learning the other had been cast.
source: John Boorman's director's commentary.
Boorman's commentary (paraphrasing): "At first I went, oh God, not Nicol Williamson. Anyone but Nicol Williamson."
I thought that was hilarious.

He was definitely the core of the film. The best Merlin and my favorite medieval movie of all time.

I agree! I've seen this film dozens of times, just for his performance. He was amazing as Merlin.

Nicol is a national treasure.

Totally agree! With his awesome voice and enigmatic charisma, Williamson was perfect for the role of the legendary Merlin.

A remarkable cinematic role from an obviously fantastic actor. Best part of the movie for me.